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'The Open Court Series of Classics of Science and 
Thilosophy^ .?{o, 2 










Copyright in Great Britain under the Act 0/1911 





I. Introduction to the Philosophy of Common 

Sense — 

§ I. The Importance of the Subject, and the Means of 

Prosecuting it • • ' t ^.x^' 

§ 2. The Impediments to our Knowledge of the 

Mind .••••' 


II. Analysis of a Typical Sensation— 

S I The Sensation considered abstractly . -37 

§ 2! Sensation and Remembrance, Natural Prin- 
ciples of BeUef • • • , ' ^^ 
§ 3. Judgment and BeUef in some Cases precede 

Simple Apprehension . • -43 

§4 Two Theories of the Nature of BeUef Refuted . 44 
8 5 Apology for Metaphysical Absurdities— Sensa- 
tion without a Sentient, a Consequence of 
the Theory of Ideas . • • -4 

§ 6. The Conception and Belief of a Sentient Bemg 
or Mind is suggested by our Constitution— 
The Notion of Relations not always got by 
comparing the Related Ideas . • 5^ 

8 7 There is a QuaUty or Virtue in Bodies, which we 
call their SmeU— How this is connected in 
the Imagination with the Sensation . 





§ 8. That there is a Principle in Human Nature, 
from which the Notion of this, as well as 
all other Natural Virtues or Causes, is derived 63 

§ 9. Whether in Sensation the Mind is Active or 

Passive ? . . . . • 70 

III. Knowledge and Reality — 

§ I. Of Hardness 

§ 2. Of Natural Signs . 

§ 3, Of Extension 

§ 4. Of the Visible Appearances of Objects 

§ 5. Of Perception in General 

§ 6. Of the Process of Nature ifi Perception 

Appendix : Of Cause and Power 

IV. The Operations of 'the Mind — 

§ I. Principles taken for Granted 

§ 2. Of Hypotheses and Analogy •' . 

§ 3. Of Perception 

§ 4. Of Sensation . . . '*> 

§ 5. Of Primary and Secondary QuaUties 

§ 6. Of Conception , 

§ 7. Of Judgment 

§ 8. Of Common Sense 

§ 9. First Principles of Contingent Truths 

§ 10. First Principles of Necessary Truths 

V. Of Morals— 











§ I. Of Benevolent Affection in General . .161 

§ 2. There are Rational Principles of Action in Man 165 
§ 3. Of Regard to Our Good on the Whole . .168 

§ 4. Of the Notion of Duty, Rectitude, Moral Obliga- 
tion ...... 173 

§ 5. Observations concerning Conscience . .182 

§ 6. That Moral Approbation implies a Real Judg- 
ment . . . . . .186 


Of Man's Progressive Nature . . -197 




Of the Perception of Truth in General . 217 


I. Of the Object of Philosophy, and the 
Method of Prosecuting Philosophical 
Inquiries ...... 229 

II. Of the Association of Ideas . . . 233 

III. Of the Power which the Mind has over 

THE Train of its Thoughts . . . 236 

IV. Of the Influence of Association on our 

Active Principles, and on our Moral 
Judgments ...... 242 

V. Of Certain Laws of Belief, inseparably 

SCIOUSNESS, Memory, Perception, and 
Reasoning ..... 249 

Index ........ 265 





The Scottish Philosophy of Common Sense origin- 
ated as a protest against the philosophy of .the 
greatest Scottish philosopher. Hume's sceptical 
conclusions did not excite as much opposition 
as might have been expected. But in Scotland 
especially there was a good deal of spoken criticism 
which was never written ; and some who would 
have liked to denounce Hume's doctrines in print 
were restrained by the salutary reflection that if 
they were challenged to give reasons for their 
criticism they would find it uncommonly difficult 
to do so. Hume's scepticism was disliked, but it 
was difficult to see how it could be adequately 

At this point Reid ^ stepped into the field. He 

^ Thomas Reid was born in 171 o at Strachan in Kincardineshire. 
His father was minister of the parish. At the age of twelve, Reid 
entered Marischal College, Aberdeen, but did not profit much by 
the teaching. After graduating in Arts, he studied Divinity, 
and was Ucensed to preach in 173 1. In 1733 he was appointed 
Librarian of Marischal College, and in 1737 was presented by 



was the only man of his time who really miderstood 
the genesis of Hume's scepticism and succeeded in 
locating its sources. At first sight it would seem 
that this discovery required no peculiar perspicuity. 
It would seem that nobody could help seeing that 
Hume's sceptical conclusions were based on Locke's 
premises, and that Hume could never be success- 
fully opposed by any critic who accepted Locke's 
assumptions. But this is precisely one of those 
obvious things that is noticed by nobody. And in 
fact Reid was the first man to see it clearly. It thus 
became his duty to question the assumptions on 
which all his own early thought had been based. 
The result of this reflection was the conclusion 
that, since the " ideal theory " of Locke and 

King's College to the living of New Machar, near Aberdeen. 
At first his parishioners were very hostile, tradition saying that 
liis uncle had to guard the pulpit stairs with a drawn sword. 
But their prejudices were gradually overcome by Reid's practical 
benevolence, though to the end they were dissatisfied with his 
sermons, which they regarded as not sufficiently original. In 
1 75 1 Reid was appointed a regent at King's College, and became 
" Professor of Philosophy," his lectures including mathematics 
and physics. He was one of the founders of the Aberdeen 
Philosophical Society (" The Wise Club "), which included among 
its members Beattie and Campbell. It was in this society that 
Reid developed his philosophy. His point of view was made 
known to the club in several papers, which were systematised 
in the Inquiry into the Human Mind on the Principles of Common 
Sense. This was published in 1764, the year in which Reid 
succeeded Adam Smith as Professor of Moral Philosophy in 
the University of Glasgow. The next sixteen years were fully 
occupied with the duties of his chair and University business. 
In 1780 he retired from his active University work, in order to 
complete his philosophical system. In 1785 appeared the 
Essays on the Intellectual Powers of Man, and three years later 
the Essays on the Active Powers of Man. The last years of his 
Ufe were devoted to mathematics and gardening, and in 1796 
he died. 


Berkeley logically led to Hume's scepticism, and 
since scepticism was intolerable, that theory would 
have to be amended, or, if necessary, abandoned. 

Reid himself gives an admirable account of the 
way in which he was roused from his dogmatic 
slumbers. " I acknowledge," he says in the 
Dedication of the Inquiry, " that I never thought 
of calling in question the principles commonly 
received with regard to the human understanding, 
until the Treatise of Human Nature was published 
in the year 1739. The ingenious author of that 
treatise upon the principles of Locke — who was no 
sceptic — hath built a system of scepticism, which 
leaves no ground to believe any one thing rather 
than its contrary. His reasoning appeared to me 
to be just ; there was therefore a necessity to call 
in question the principles upon which it was founded, 
or to admit the conclusion." ^ Reid was deter- 
mined not to acquiesce in the sceptical conclusion. 
And that for three reasons. Scepticism, he says, 
is trebly destructive. It destroys the science of a 
philosopher, it undermines the faith of a Christian, 
and it renders nugatory the prudence of a man of 
common understanding. Thus he was forced to 
undertake a criticism of the assumptions on which 
that sceptical conclusion was based. " For my 
own satisfaction, I entered into a serious examina- 
tion of the principles upon which this sceptical 
1 Works, vol. i. p. 95. 


system is built ; and was not a little surprised to 
find that it leans with its whole weight upon a 
hypothesis which is ancient indeed, and hath been 
very generally received by philosophers, but of 
which I could find no solid proof." ^ This hypo- 
thesis is to be found in Locke and Descartes, and 
consists in the postulation of a world of ideas inter- 
mediate between the knower and the object known. 
It is from this hypothesis, says Reid, that Hume's 
scepticism directly results. Reid therefore really 
criticises Hume via Locke. He takes up the position 
that if Locke's assumption be proved untenable, 
Hume's conclusion will fall to the ground. Thus, 
while it is true that it was Hume who elicited Reid's 
philosophy, that philosophy is not so much a direct 
** answer to Hume " as an answer to Locke. 

Now, Locke's doctrine admitted of two, and only 
two, answers. One of these was given by Berkeley, 
and led to the scepticism of Hume. The other was 
given by Reid. For Locke perception involves 
three elements : the percipient, the idea perceived, 
and the thing ; and it is assumed that the idea is 
somehow a copy of the external reality. Both 
Berkeley and Reid saw clearly the difficulties of 
the doctrine of Representative Perception. If the 
mind is confined to its own ideas and is cut off from 
immediate knowledge of the real world, how is it 
to know if its ideas do or do not agree with things ? 

^ Works, vol. i. p. 96. 


In order to compare two things, it is necessary to 
know both. Thus we cannot compare ideas with 
the things which they represent, because we can 
never escape the circle of our own ideas. And the 
further objection is advanced that if the external 
world does exist, it cannot be like our ideas, for 
nothing but an idea can be like an idea. Both 
Berkeley and Reid saw these difficulties in Locke's 
doctrine. They both agreed that Locke had gone 
wrong. How he had gone wrong was the question 
on which they differed. They agreed, it is true, 
that Locke had obscured the nature of knowledge 
by interpolating a spurious factor. But they 
differed toto ccelo with regard to the question 
which of Locke's factors was unreal. By Berkeley 
it was maintained that Locke's third factor — the 
material world — had no real existence. But Reid 
denied the existence of Locke's second factor. 
Locke's imitative and intermediate ideas are simply 
creatures of phantasy : they have no real existence. 
Thus Berkeley is left with mind plus ideas, and 
Reid with mind plus matter. For both, the relation 
between mind and its object is immediate. 

Reid naturally regarded his own answer to Locke 
as better than Berkeley's, partly because Hume 
had argued that Berkeley's criticisms of Locke's 
material substance could with equal force be 
levelled against Berkeley's own spiritual substance ; 
and partly because he believed that a world which 


consists of minds plus matter is more " consen- 
taneous " with common sense than one which 
contains only minds plus ideas. Neither of these 
reasons, in point of fact, is sound, though both 
would have been perfectly valid if Berkeley had 
really meant what Hume and Reid thought that he 
meant. It ought to be remembered, when Reid 
is criticised for his vulgar failure to appreciate 
the point of Berkeley's argument, that Hume also 
did not fully understand it. Berkeley takes special 
pains in the Three Dialogues between Hylas and 
Philonous to answer precisely the criticisms that 
Reid and Hume advanced. He points out, for 
instance, that his arguments against material 
substance cannot be successfully used against 
spiritual substances, for spirits are not inert and 
passive, but are active beings, which are not known 
as ideas, but are apprehended through notions. 
Hume's criticism of Berkeley simply makes the 
unjustifiable assumption that spirits are on the 
same level as ideas, and that they are known in 
the same way. Reid's misapprehension of Berke- 
ley's meaning is neither more nor less egregious. 
He assumes that in denying the existence of matter, 
and in asserting that the world consists solely of 
spirits and ideas, Berkeley is proclaiming the non- 
existence of the world to which common sense 
bears testimony. Now, Reid knew that Berkeley 
was never weary of insisting that his doctrine 


denied nothing that common sense admitted. The 
material world which Berkeley destroyed was not a 
conviction of common sense, but a philosophical 
hypothesis. For him the world remained as real 
as ever. If Hume and Reid had been less eager 
to criticise Berkeley and more anxious to under- 
stand him, they might have seen the importance 
of the suggestions made by him — e.g. in the second 
edition of the Principles and in Siris — towards an 
interpretation of the world based on the concur- 
rence of both reason and sense. Hume entirely 
failed to appreciate Berkeley's suggestions towards 
a notional system of knowledge, and, if Reid 
noticed them, he made no use of them in the de- 
velopment of his own system. 

The great merit of Reid's answer to Locke lay 
in its immunity from criticism along Hume's lines. 
By denying the existence of ideas in Locke's sense, 
it entirely cut the ground away from Hume. Reid 
himself points out that his own doctrine, in one 
aspect, forms the reductio ad absurdum of the whole 
" ideal theory." Locke starts with minds, ideas, 
and matter. Berkeley disproves matter and re- 
tains minds and ideas. Hume denies the existence 
of minds and preserves only ideas. And Reid in 
turn denies ideas. Thus the development of 
thought has, by a necessary process, led to the 
destruction of the whole apparatus with which 
Locke started. Reid therefore resolves to begin 


afresh, not with hypotheses postulated by philo- 
sophy, but with principles guaranteed by common 

It may have been noticed that in this account of 
the development of Reid's thought with reference 
to his immediate predecessors, two slightly different 
views have been implied. So far these have 
purposely not been distinguished. For it is 
probable that the actual development of Reid's 
own views was determined in the way sketched 
above, partly by direct opposition to Hume and 
partly by criticism of Locke. It is probable that 
he was not clearly conscious how far his views owed 
their origin to criticism of Locke, and how far to 
antagonism to Hume. But it is worth while to 
make the difference clear. If we regard Reid's 
doctrine as developed mainly by criticism of Locke's 
assumptions, it can be shewn that it retains more 
of the Descartes-Locke assumptions than it denies. 
In particular, Reid preserves, though he restates, 
the two-substance doctrine, which was one of the 
most important elements in the Locke-Descartes 
Gemeingut, In one aspect, then, Reid may be 
regarded as Locke purged and Locke re-created. It 
is only a mild exaggeration to say that Reid's 
system is a critical reconstruction of Locke. 

But when Reid's work is considered in its direct 
application to Hume, it assumes a somewhat 
different tinge. It then appears more closely 


related to the uncritical appeals to common sense 
made by Reid's contemporaries and successors. 
Reid saw that some of Hume's conclusions were 
ridiculous, and he believed that others were im- 
pious ; and he was apt to assume that their apparent 
absurdity and impiety supplied adequate grounds 
for denying them. Reid appealed from the hypo- 
theses of philosophy to the ** principles of common 
sense." Common sense secured to him the belief 
in the existence of mind and matter. From this 
naive dualism was developed his Natural Realism. 
Such is another view that may be taken of the 
genesis of Reid's doctrine. 

The truth lies somewhere between the two 
sharply contrasted views. The distinction between 
them was almost certainly hardly present to Reid's 
own mind. But the former is nearer the truth than 
the latter. It cannot be denied that there is a Reid 
who in the Inquiry and even in the Essays appeals 
from philosophy, in the manner of Beattie and 
Oswald, to vulgar common sense. There is a Reid 
who condemns a theory by consigning its author 
to the mad-house. There is a Reid who gets rid 
of difficulties by simply laughing at them. But 
this is not the normal Reid. When the normal 
Reid appeals to common sense, it is an appeal 
not to blind feeling, but to permanent principles 
of human nature. He makes an appeal, as Sir 
William Hamilton has said, ** from the heretical 


conclusions of particular philosophies to the catho- 
lic principles of all philosophy." ^ Further, while 
it is perfectly true that Reid's nisus to inde- 
pendent philosophical inquiry was due to his 
desire to rebut Hume's conclusions, and while 
he did criticise Hume directly, he had acuteness 
enough to see that the only really successful 
criticism of Hume must be Higher Criticism, in 
the strict sense of that much-abused term, i.e. 
criticism higher upstream, nearer the source. 

Reid's work was both constructive and critical. 
He did not start absolutely de novo with the con- 
victions of common sense. What he did was to 
take over, in large measure, the results of Locke's 
work, at the same time subjecting it to examination 
in the light of all the information he could himself 
acquire by a common-sense investigation of mental 
processes. Nothing could be truer than Sidgwick's 
statement, " If Locke is the first founder of the 
distinctively British science. Empirical Psychology, 
of which the primary method is introspective 
observation and analysis, I think Reid has a fair 
claim to be regarded as a second founder." ^ 

Much less favourable was the judgment that Kant 
passed on Reid. In the Prolegomena to Any Future 
Metaphysic, Kant declares that Reid entirely 
missed the point of Hume's problem. What Reid 
ought to have done, says Kant, was to " probe 

1 Reid's Works, vol. ii. p. 751. ^ Mind, 1895, p. 153. 


more deeply into the nature of reason." But, 
instead of doing this, he " discovered a more con- 
venient means of putting on a bold face without 
any proper insight into the question, by appealing 
to the common sense of mankind." Such an appeal 
to common sense, Kant continues, had the effect 
of enabling the emptiest babbler without an atom 
of insight to attack with some show of success a 
thinker of Hume's calibre. Now, it seems in- 
conceivable that, if Kant had really read Reid, he 
could have written about him in such a strain. And 
it has been suggested that in all probability Kant 
had no first-hand knowledge of Reid. In the 
Prolegomena he mentions Reid along with Oswald, 
Beattie, and Priestley, making no distinction 
between them. But if Kant had himself read 
the writings of these men, he could hardly have 
bracketed them, for Reid is altogether in a different 
class from the other three. Hence the very 
plausible suggestion, supported by the way in 
which Kant mentions the names (" Reid, Oswald, 
Beattie, and even Priestley "), that Kant's know- 
ledge of Reid was derived solely from the criticisms 
in Priestley's Examination. 

But Hume had certainly read Reid, and it is 
interesting to compare his criticism with Kant's. 
Hume received, from a common friend (Dr Blair), 
parts of the manuscript of Reid's Inquiry. He 
started to read it with no enthusiasm, muttering a 


wish '* that the parsons would confine themselves 
to their old task of worrying one another, and 
leave philosophers to argue with moderation, 
temper, and good manners." But the book itself 
entirely dissolved Hume's prejudice, and elicited 
a generous and appreciative letter to Reid. *' It 
is certainly very rare," Hume writes, ** that a 
piece so deeply philosophical is wrote with so much 
spirit, and affords so much entertainment to the 
reader. . . . There are some objections that I 
would propose, but I will forbear till the whole 
can be before me. I will only say that if you have 
been able to clear up these abstruse and important 
topics, instead of being mortified, I shall be so vain 
as to pretend to a share of the praise." The point 
specially worth noticing in this testimony is the 
fact that Hume remarks on the '* deeply philo- 
sophical " character of Reid's work. He does 
not dream of talking of " empty babblers " : in 
particular, it does not occur to him that Reid had 
appealed from scientific philosophy to vulgar 
common sense. He recognises that Reid's attack 
on him is a damaging criticism, made on the strictly 
philosophical level. 

The analogies between Reid's work and Kant's 
are many and striking. Reid began, as Kant did, 
by comparing the slow progress made by philo- 
sophy with the rapid advance of physical science. 
And, like Kant, Reid determined that, if philo- 


sophy were to advance, the attitude of physical 
science must be adopted. Like Kant, Reid was 
a competent mathematician and physicist, with a 
great respect for Newton. But his general philo- 
sophical method differs from that of Kant. While 
Kant's work is written, in the main, from the 
epistemological standpoint, Reid remains true to 
the traditional British psychological method. The 
philosopher must undertake an examination of the 
operations of the mind. He is an anatomist of the 
mind. His task is much more difficult than that 
of the student of the anatomy of the body, *' for 
it is his own mind only that he can examine with 
any degree of accuracy and distinctness." ^ Philo- 
sophy is based on the results of our introspective 
observation of the working of our own minds. 

Reid's critique of knowledge, like Kant's, opposes 
any sensationalism such as Hume's. Hume main- 
tained that the mind and its objects can be reduced 
to a series of particular sensations, and that these 
individual sensations may be known, each inde- 
pendent of the other. Reid criticises this view, to 
which he gives the scholastic name *' simple appre- 
hension." It is a mistake to think, he says, that 
knowledge consists originally in simple apprehen- 
sion. ^ It is a mistake to think that we start origin- 
ally with simple sensations and then refer them 
to their subjects and their objects. On the con- 

1 Works, vol. i. p. 98. 2 Ibid., p. 106. 


trary, the simplest act of the mind is already a 
judgment. Judgment is both logically and psycho- 
logically prior to simple apprehension. Judgment 

/ is the unit of knowledge. By a process of analysis, 
it is possible to differentiate elements within the 
judgment. But these elements are elements 
merely ; and they can be regarded separately 
only by a process of abstraction. Thus even 
simple apprehension is not really simple : it is 
reached by abstraction from the natural unit of 
knowledge. If we analyse even the simplest sen- 
sation, we find that it always implies judgment. 

In the Inquiry Reid proves this in detail, by an 
examination of the five external senses. He begins 
with smell, the simplest and least intellectual of 
these, and shows that even here a system of natural 
judgments is suggested. These natural judgments 
are not actually given in experience : they are 

, suggested by experience. The natural judgments 
thus suggested are necessary for the constitution 
of experience. Were sense-experience not accom- 
panied by these natural suggestions, it would itself 
be an impossibility. What are these constitutive 
natural judgments ? There is the judgment, in 
the first place, of existence. Our sensations im- 
mediately suggest that what we now feel or perceive 
actually exists, and memory suggests that what we 
remember did actually exist. But this judgment 
of existence does not mean that what we feel exists 


only as a sensation. It implies the permanent 
existence of {a) minds and [h) the material world. 
Reid admits that we cannot logically infer the exist- 
ence either of minds or of the external world. But 
he insists that they are principles of common sense, 
" They are judgments of nature — judgments not 
got by comparing ideas and perceiving agreements 
and disagreements, but immediately inspired by 
our constitution." ^ 

Another natural judgment is that there is a real 
difference between primary and secondary qualities. 
Reid points out that Berkeley's arguments against 
the distinction must be regarded as conclusive by 
all who agree with the " ideal theory." *' Yet, 
after all," he says, " there appears to be a real 
foundation for it in the principles of our nature." ^ 
He draws a sharp distinction between sensible 
qualities and sensations. The almost universal 
tendency to confuse the external quality with the 
sensation is due to the fact that we have no name 
for the sensation, as distinct from the perceived 
quality. But Reid insists that, though we draw 
no distinction in language, the distinction does 
really exist. For example, our sensation of hard- 
ness is quite distinct from the hardness which really 
exists in bodies. ** Hitherto, they have been con- 
founded by the most acute enquirers into the 
principles of human nature, although they appear, 

1 Works, vol. i. p. no. 2 /jj^,^ vol. i. p. 123. 


upon accurate reflection, not only to be different 
things, but as unlike as pain is to the point of a 
sword." ^ In every case the sensible quality must 
be distinguished from the sensation ; and in no 
case is the sensible quality dependent for its exist- 
ence on the sensation. Reid really obscures the 
distinction between primary and secondary quali- 
ties, though in a different way from Berkeley. 
Berkeley had reduced all qualities to secondary 
qualities : Reid, in effect, makes all qualities 
primary. Thus colour means, he says, ** not a 
sensation of the mind, which can have no existence 
when it is not perceived, but a quality or modifica- 
tion of bodies, which continues to be the same, 
whether it is seen or not." ^ Eventually, after 
considering in detail in the Inquiry various primary 
and secondary qualities, the only difference Reid 
finds between them is that there is a resemblance 
and a necessary connection between primary 
qualities and the sensations we have of them, but 
not between secondary qualities and our sensations. 
In the Essays Reid attacks the problem again, and 
adds that our senses give us a direct and distinct 
notion of primary qualities, but of secondary 
qualities only a relative and obscure notion. 
The important point is not so much Reid's attempt 
to distinguish primary from secondary qualities 
as his insistence on the fact that in both cases our 

1 Works, vol. i. p. 122. * Ibid., vol. i. p. 137. 


sensations are generically different from the quali- 
ties of things. Hence mere sensation can never 
give us knowledge of an object : for that, perception 
is necessary. Reid is far from consistent in main- 
taining the distinction between perception and 
sensation ; but in the main he holds that while 
sensation is the condition of perception, yet bare 
sensation by itself neither is an object of knowledge 
nor can give complete knowledge of an object. In 
all knowledge, he holds, is involved the perceptual 
activity of the self, working in accordance with 
certain natural judgments. It will be evident how 
far this theory is in general agreement with Kant's 
doctrine of the importance of judgment, and the 
in dispensability for knowledge of the subject with 
its categories. 

Reid's contemporaries and successors in the 
Scottish School made little, if any, real contribution 
to the Philosophy of Common Sense. He was the 
greatest, as he was the first, of the School; and its other 
members were content, for the most part, to repeat in 
other words what he had already said. Reid was the 
most strictly philosophical member of the school. 
The extracts in this volume, though they reveal the 
other thinkers at their best , make that sufficiently clear. 

Beattie ^ in his own day far surpassed Reid in 
reputation : this was largely due to what may now 

1 James Beattie was born in 1735, and in 1749 went to Marischal 
College, Aberdeen. His circumstances were narrow, and on 
graduation he took a post as schoolmaster at Fordoun, Kin- 



be regarded as his most serious defects, the lack of 
** body " in his work, and his vulgar denunciations 
of Hume. Beattie's popularity in his own day had 
a good deal to do, as Stewart points out, with the 
bad odour in which the Philosophy of Common 
Sense came to be held. Beattie was regarded as its 
chief exponent, and his uncritical work was considered 
typical of the Scottish philosophy. His Essay on the 
Nature and Immutability of Truth is a rather foolish 
and vulgar attack on Hume's scepticism, but it was 
appreciated more than Reid's work by those who, 
like George III., were not peculiarly intelligent. 
Ferguson's ^ work betrays the same thinness and 

cardineshire, where he became acquainted with Lord Monboddo. 
In 1760 he was appointed Professor of Moral Philosophy in 
Marischal College, where he became a member of Reid's " Wise 
Club." Beattie was a poet by choice and a philosopher only by 
profession. He himself preferred his poetry to his philosophy, 
but in this judgment he was not supported by the pubhc. The 
Essay on Truth, published in 1770, passed through five large 
editions in four years. Beattie came to be regarded as the 
defender of the faith, and all sorts of honours were showered on 
him. He continued to lecture at Aberdeen till 1797, when he 
became too ill to do even occasional lecturing. He died in 1803. 
1 Adam Ferguson was born in 1723 at Logierait, Perthshire, 
where his father was minister of the parish. Passing through 
the Universities of St Andrews and Edinburgh, he was appointed 
in 1745 Chaplain to the Black Watch, being present at the battle 
of Fontenoy, and, according to legend, leading the regiment into 
action, drawn broadsword in hand. In 1757 he succeeded Hume 
in the Librarianship of the Advocates' Library, which he held for 
less than a year. In 1759 he became Professor of Natural 
Philosophy in Edinburgh University, and in 1764 was trans- 
ferred to the chair of moral philosophy. He contrived, while 
retaining his chair, to engage in several controversies, undertake 
the tuition of noblemen's sons, and perform various Government 
services, involving trips on the Continent and to Philadelphia. 
He resigned his Professorship in 1785, and died in 1816. His 
works include Essay on Civil Society (1766), Institutes of Moral 
Philosophy (1772), Principles of Moral and Political Science (1792). 


lack of originality as Beattie's. He himself de- 
scribes his Principles of Moral and Political Science 
as " much of what everybody knows about mind." 
At the same time, it must be remembered that it 
was he who promulgated the " perf ectibilianism " 
which had a considerable vogue at the time as an 
ethical theory. 

Stewart ^ gave a very clear and scholarly re- 
statement of the principles of the Common-Sense 
Philosophy. A man of great erudition and much 
personal charm, and easily the foremost philosopher 
of the day in Britain, he did more than anyone else 
not merely to popularise that philosophy, but to 
secure for it the respectful, and, in some cases, the 
admiring, attention of other philosophers. His re- 
chauffe of Reid is often overburdened with illustra- 
tion and analogy. But there are points on which 
he states the common yiews of the school in a more 

^ Dugald Stewart was born in 1753 at Edinburgh, where his 
father was Professor of Mathematics. In 1765 he entered the 
University, became a good mathematician, and came under the 
influence of Adam Ferguson. Ferguson had warmly welcomed 
Reid's Inquiry, and thus from the beginning Stewart was brought 
to regard Reid as the chief authority in philosophy. In 1771 
he went to Glasgow and attended Reid's lectures. The next 
session saw him again in Edinburgh, taking charge of his father's 
mathematical classes. In 1785 he was transferred to the chair 
of moral philosophy. He rapidly acquired great influence 
both in the general society of Edinburgh, and in the philosophical 
world. James Mill says that neither Pitt nor Fox was nearly 
so eloquent. He was a proHfic writer, beginning with the 
Elements of the Philosophy of the Human Mind, the first volume 
of which was published in 1792, and ending with the Philosophy 
of the Active and Moral Powers of Man in 1828. He retired from 
the active duties of the chair in 1809 ; and thenceforward, till 
his death in 1828, occupied himself with literary work. 


systematic and thorough way than Reid. In 
particular may be mentioned the sections on Taste, 
which show aesthetic appreciation and real origin- 
ality, and the chapter on the ** Fundamental Laws 
of Human Belief," which contains a fresh restate- 
ment of the '* principles of common sense." 

Other representatives of the Philosophy of Com- 
mon Sense are Campbell and Oswald. George 
Campbell (1719-1796), one of the original members 
of Reid's '* Wise Club," incorporated his contribu- 
tions to the society in his Philosophy of Rhetoric^ 
(1776). James Oswald published in 1766-1772 
An Appeal to Common Sense in hehalf of Religion, 
a popular vindication of religion and morality. 
They simply follow Reid, and apply his views 
without making any real contributions to the 
Philosophy of Common Sense. Like his contem- 
poraries, Lord Monboddo (1714-1799) was opposed 
to the Locke - Berkeley - Hume development of 
thought, but he did not agree with Reid that its 
sceptical conclusions could be met by an appeal 
to common sense. In his Antient Metaphysics he 
advocated a " return to Plato " as the only means 
of defeating scepticism. Thomas Brown (1778- 
1820) and Sir William Hamilton (1788-1856) are 
sometimes classed with the common-sense philo- 
sophers ; but they both abandoned many of its 
most important positions. Brown's philosophy has 
interest now mainly as an anticipation of the associa- 


tion psychology, and almost everything he added to 
the Scottish philosophy was inconsistent with it. 
Sir William Hamilton was much influenced by 
German philosophy, especially that of Kant. His 
" Natural Realism " is a strange mixture of Reid and 
Kant, and he should not be regarded as a repre- 
sentative of the Philosophy of Common Sense. 

In Reid's followers the weaknesses and defects 
of the Scottish philosophy emerge with special 
clearness, but even in Reid himself they are 
sufficiently noticeable. As they are so obvious, it 
is the less necessary to labour them. But three or 
four of them may be simply mentioned. The 
Scottish philosophers are apt to turn, in difficulties, 
to vulgar, uncritical common sense. They are apt 
to set up an opposition between philosophy and 
common sense, and to appeal from the verdict of 
philosophy to the bar of common sense. / They 
are apt to regard as the principles of common sense 
simply those principles which to them seem to be 
self-evident, j Again, they are too ready to acquiesce 
in the ultimate inexplicability of their principles. 
No attempt is made to prove or deduce the system 
of natural judgments. There seems to be no reason 
why there should be so many and no more. In the 
works of all the representatives of the school, again 
and again one meets with assertions of the final 
inability of philosophy to explain the why and 
wherefore of things. Further, they are very care- 


less in the use of terms. While it is of funda- 
mental importance for the school to distinguish 
between perception and sensation, and while every 
one of the writers does distinguish between them 
officially, they often use the terms indiscriminately 
and ambiguously. Perception and conception are 
often confused, and also conception and imagina- 
tion. The school does have a definite terminology, 
but too often it uses its terms loosely. 

The historical significance of the Philosophy of 
Common Sense is considerable. In England and 
Germany it has never been much appreciated, but 
in France it has exercised a great influence. Royer- 
CoUard (1763-1845) introduced it to his country- 
men, and, through his great pupil Victor Cousin 
(1792-1867), made it the greatest power in the 
French philosophy of the period. Cousin's work 
was supported by Jouffroy (1796-1842), who trans- 
lated Reid's works into French. For half a century 
the Philosophy of Common Sense was the dominant 
philosophy in the American Universities, and it 
is to the Scottish President of an American College 
that we owe the most comprehensive study of it. 
In recent years in France there has been a re- 
crudescence of interest in the Scottish philosophy, 
an interest which has extended to the writings of 
Professor S. S. Laurie, who, in several able works, 
attempted what amounts to a critical reconstruction 
of the traditional Scottish Natural Realism. 


The selections in this volume are reprinted from 
the following editions : — 

Reid's Works, edited by Sir William Hamilton, 
sixth edition, 1863. 

Beattie's Essay on the Nature and Immutability 
of Truth, seventh edition, 1807. 

Ferguson's Principles of Moral and Political 
Science, 1792. 

Stewart's Collected Works, edited by Sir William 
Hamilton, 1854-1858. 

The following books may be consulted : — 

J. M'Cosh, The Scottish Philosophy, London, 


A. S. Pringle - Pattison, Scottish Philosophy, 
fourth edition, Edinburgh, 1907. 

H. Laurie, Scottish Philosophy in its National 
Development, Glasgow, 1902. 

A. Campbell Fraser, Thomas Reid, Edinburgh, 




§ I. The Importance of the Subject, and the 
Means of Prosecuting It 

The fabric of the human mind is curious and won- 
derful, as well as that of the human body. The 
faculties of the one are with no less wisdom adapted 
to their several ends than the organs of the other. 
Nay, it is reasonable to think, that, as the mind is a 
nobler work and of a higher order than the body, 
even more of the wisdom and skill of the divine 
Architect hath been employed in its structure. 
It is, therefore, a subject highly worthy of in- 
quiry on its own account, but still more worthy 
on account of the extensive influence which the 
knowledge of it hath over every other branch of 

In the arts and sciences which have least con- 
nection with the mind, its faculties are the engines 
which we must employ ; and the better we under- 
stand their nature and use, their defects and 



disorders, the more skilfully we shall apply them, 
and with the greater success. But in the noblest 
arts, the mind is also the subject upon which we 
operate. The painter, the poet, the actor, the 
orator, the moralist, and the statesman, attempt 
to operate upon the mind in different ways, and for 
different ends ; and they succeed according as they 
touch properly the strings of the human frame. 
Nor can their several arts ever stand on a solid 
foundation, or rise to the dignity of science, until 
they are built on the principles of the human 

Wise men now agree, or ought to agree, in this, 
that there is but one way to the knowledge of 
nature's works — the way of observation and experi- 
ment. By our constitution, we have a strong 
propensity to trace particular facts and observa- 
tions to general rules, and to apply such general 
rules to account for other effects, or to direct us 
in the production of them. This procedure of the 
understanding is familiar to every human creature 
in the common affairs of life, and it is the only 
one by which any real discovery in philosophy can 
be made. 

The man who first discovered that cold freezes 
water, and that heat turns it into vapour, pro- 
ceeded on the same general principles, and in the 
same method by which Newton discovered the law 
of gravitation and the properties of light. His 

REID 29 

regulcB philosophandi are maxims of common sense, 
and are practised every day in common life ; and 
he who philosophizes by other rules, either con- 
cerning the material system or concerning the mind, 
mistakes his aim. 

Conjectures and theories are the creatures of 
men, and will always be found very unlike the 
creatures of God. If we would know the works 
of God, we must consult themselves with attention 
and humility, without daring to add anything of 
ours to what they declare. A just interpretation 
of nature is the only sound and orthodox philo- 
sophy : whatever we add of our own is apocryphal, 
and of no authority. 

All our curious theories of the formation of the 
earth, of the generation of animals, of the origin of 
natural and moral evil, so far as they go beyond a 
just induction from facts, are vanity and folly, no 
less than the Vortices of Des Cartes, or the Archaeus 
of Paracelsus. Perhaps the philosophy of the mind 
hath been no less adulterated by theories, than 
that of the material system. The theory of Ideas 
is indeed very ancient, and hath been very univer- 
sally received ; but, as neither of these titles can 
give it authenticity, they ought not to screen it 
from a free and candid examination ; especially 
in this age, when it hath produced a system of 
scepticism that seems to triumph over all science, 
and even over the dictates of common sense. 


All that we know of the body, is owing to ana- 
tomical dissection and observation, and it must be 
by an anatomy of the mind that we can discover its 
powers and principles. 

§ 2. The Impediments to our Knowledge 
OF THE Mind 

But it must be acknowledged, that this kind of 
anatomy is much more difficult than the other ; 
and, therefore, it needs not seem strange that man- 
kind have made less progress in it. To attend 
accurately to the operations of our minds, and make 
them an object of thought, is no easy matter even 
to the contemplative, and to the bulk of mankind 
is next to impossible. 

An anatomist who hath happy opportunities, 
may have access to examine with his own eyes, and 
with equal accuracy, bodies of all different ages, 
sexes, and conditions ; so that what is defective, 
obscure, or preternatural in one, may be discerned 
clearly and in its most perfect state in another. 
But the anatomist of the mind cannot have the 
same advantage. It is his own mind only that he 
can examine with any degree of accuracy and 
distinctness. This is the only subject he can look 
into. He may, from outward signs, collect the 
operations of other minds ; but these signs are for 
the most part ambiguous, and must be interpreted 
by what he perceives within himself. 

REID 31 

So that, if a philosopher could delineate to us, 
distinctly and methodically, all the operations of 
the thinking principle within him, which no man 
was ever able to do, this would be only the anatomy 
of one particular subject ; which would be both de- 
ficient and erroneous, if applied to human nature 
in general. For a little reflection may satisfy us, 
that the difference of minds is greater than that of 
any other beings which we consider as of the same 

Of the various powers and faculties we possess, 
there are some which nature seems both to have 
planted and reared, so as to have left nothing to 
human industry. Such are the powers which we 
have in common with the brutes, and which are 
necessary to the preservation of the individual, or 
the continuance of the kind. There are other 
powers, of which nature hath only planted the seeds 
in our minds, but hath left the rearing of them to 
human culture. It is by the proper culture of these 
that we are capable of all those improvements in 
intellectuals, in taste, and in morals, which exalt 
and dignify human nature ; while, on the other hand, 
the neglect or perversion of them makes its degener- 
acy and corruption. 

The two-legged animal that eats of nature's 
dainties, what his taste or appetite craves, and 
satisfies his thirst at the crystal fountain, who 
propagates his kind as occasion and lust prompt. 


repels injuries, and takes alternate labour and 
repose, is, like a tree in the forest, purely of nature's 
growth. But this same savage hath within him 
the seeds of the logician, the man of taste and 
breeding, the orator, the statesman, the man of 
virtue, and the saint ; which seeds, though planted 
in his mind by nature, yet, through want of culture 
and exercise, must lie for ever buried, and be 
hardly perceivable by himself or by others. 

The lowest degree of social life will bring to light 
some of those principles which lay hid in the savage 
state ; and, according to his training, and company, 
and manner of life, some of them, either by their 
native vigour, or by the force of culture, will thrive 
and grow up to great perfection, others will be 
strangely perverted from their natural form, and 
others checked, or perhaps quite eradicated. 

This makes human nature so various and multi- 
form in the individuals that partake of it, that, in 
point of morals and intellectual endowments, it 
fills up all that gap which we conceive to be between 
brutes and devils below, and the celestial orders 
above ; and such a prodigious diversity of minds 
must make it extremely difficult to discover the 
common principles of the species. 

The language of philosophers, with regard to the 
original faculties of the mind, is so adapted to the 
prevailing system, that it cannot fit any other ; like 
a coat that fits the man for whom it was made. 

REID 33 

and shews him to advantage, which yet will sit 
very awkward upon one of a different make, 
although perhaps as handsome and as well pro- 
portioned. It is hardly possible to make any 
innovation in our philosophy concerning the mind 
and its operations, without using new words and 
phrases, or giving a different meaning to those that 
are received — a liberty which, even when necessary, 
creates prejudice and misconstruction, and which 
must wait the sanction of time to authorize it ; for 
innovations in language, like those in religion and 
government, are always suspected and disliked by 
the many, till use hath made them familiar, and pre- 
scription hath given them a title. 

If the original perceptions and notions of the 
mind were to make their appearance single and 
unmixed, as we first received them from the hand 
of nature, one accustomed to reflection would have 
less difficulty in tracing them ; but before we are 
capable of reflection, they are so mixed, compounded, 
and decompounded, by habits, associations, and 
abstractions, that it is hard to know what they were 
originally. The mind may, in this respect, be 
compared to an apothecary or a chemist, whose 
materials indeed are furnished by nature ; but, 
for the purposes of his art, he mixes, compounds, 
dissolves, evaporates, and sublimes them, till they 
put on a quite different appearance ; so that it is 
very difficult to know what they were at first, and 



much more to bring them back to their original 
and natural form. And this work of the mind is 
not carried on by deliberate acts of mature reason, 
which we might recollect, but by means of instincts, 
(/ habits, associations, and other principles, which 
operate before we come to the use of reason ; so 
that it is extremely difficult for the mind to return 
upon its own footsteps, and trace back those 
operations which have employed it since it first 
began to think and to act. 

Could we obtain a distinct and full history of all 
that hath past in the mind of a child, from the 
beginning of life and sensation, till it grows up to 
the use of reason — how its infant faculties began to 
work, and how they brought forth and ripened 
all the various notions, opinions, and sentiments 
which we find in ourselves when we come to be 
capable of reflection — this would be a treasure 
of natural history, which would probably give 
more light into the human faculties, than all the 
systems of philosophers about them since the 
beginning of the world. But it is in vain to wish 
for what nature has not put within the reach of our 
power. Reflection, the only instrument by which 
we can discern the powers of the mind, comes too 
late to observe the progress of nature, in raising 
them from their infancy to perfection. 

It must therefore require great caution, and great 
application of mind, for a man that is grown up 

REID 35 

in all the prejudices of education, fashion, and 
philosophy, to unravel his notions and opinions, 
till he find out the simple and original principles 
of his constitution, of which no account can be 
given but the will of our Maker. This may be truly 
called an analysis of the human faculties ; and, till 
this is performed, it is in vain we expect any just 
system of the mind — that is, an enumeration of 
the original powers and laws of our constitution, 
and an explication from them of the various 
phaenomena of human nature.^ 

Des Cartes, Malebranche, and Locke, have all 
employed their genius and skill to prove the exist- 
ence of a material world ; and with very bad 
success. Poor untaught mortals believe undoubt- 
edly that there is a sun, moon, and stars ; an earth, 
which we inhabit ; country, friends, and relations, 
which we enjoy ; land, houses, and moveables, 
which we possess. But philosophers, pitying the 
credulity of the vulgar, resolve to have no faith 
but what is founded upon reason. They apply to 
philosophy to furnish them with reasons for the 
belief of those things which all mankind have 
believed, without being able to give any reason for 
it. And surely one would expect, that, in matters 
of such importance, the proof would not be difficult : 
but it is the most difficult thing in the world. For 
these three great men, with the best good will, 

^ " Inquiry into the Human Mind," Works, vol. i. pp. 97-99. 


have not been able, from all the treasures of philo- 
sophy, to draw one argument that is fit to convince 
a man that can reason, of the existence of any one 
thing without him. Admired Philosophy ! daughter 
of light ! parent of knowledge and wisdom ! if thou 
art she, surely thou hast not yet arisen upon the 
human mind, nor blessed us with more of thy rays 
than are sufficient to shed a darkness visible upon 
the human faculties, and to disturb that repose 
and security which happier mortals enjoy, who 
never approached thine altar, nor felt thine in- 
fluence ! But if, indeed, thou hast not power to 
dispel these clouds and phantoms which thou hast 
discovered or created, withdraw this penurious and 
malignant ray ; I despise Philosophy, and renounce 
its guidance — let my soul dwell with Common Sense. ^ 
It may be observed, that the defects and blem- 
ishes in the received philosophy concerning the 
mind, which have most exposed it to the contempt 
and ridicule of sensible men, have chiefly been 
owing to this — that the votaries of this Philosophy, 
from a natural prejudice in her favour, have en- 
deavoured to extend her jurisdiction beyond its 
just limits, and to call to her bar the dictates of 
Common Sense. But these decline this juris- 
diction ; they disdain the trial of reasoning, and 
disown its authority ; they neither claim its aid, 
nor dread its attacks. 

* Ibid., pp. loo-ioi. 

REID 37 

In this unequal contest betwixt Common Sense 
and Philosophy, the latter will always come off 
both with dishonour and loss ; nor can she ever 
thrive till this rivalship is dropt, these encroach- 
ments given up, and a cordial friendship restored : 
for, in reality, Common Sense holds nothing of 
Philosophy, nor needs her aid. But, on the other 
hand. Philosophy (if I may be permitted to change 
the metaphor) has no other root but the principles 
of Common Sense ; it grows out of them, and draws 
its nourishment from them.^ 


§ I. The Sensation considered abstractly 

Let us now attend carefully to what the mind 
is conscious of when we smell a rose or a lily ; and, 
since our language affords no other name for this 
sensation, we shall call it a smell or odour, carefully 
excluding from the meaning of those names every- 
thing but the sensation itself, at least till we have 
examined it. 

Suppose a person who never had this sense before, 
to receive it all at once, and to smell a rose — can 
he perceive any similitude or agreement between 
the smeU and the rose ? or indeed between it 
and any other object whatsoever ? Certainly he 
cannot. He finds himself affected in a new way, 

* Ibid., p. loi. 


he knows not why or from what cause. Like a man 
that feels some pain or pleasure formerly unknown 
to him, he is conscious that he is not the caaise of it 
himself ; but cannot, from the nature of the thing, 
determine whether it is caused by body or spirit, 
by something near, or by something at a distance. 
It has no similitude to anything else, so as to admit 
of a comparison ; and, therefore, he can conclude 
nothing from it, unless, perhaps, that there must be 
some unknown cause of it. 

It is evidently ridiculous to ascribe to it figure, 
colour, extension, or any other quality of bodies. 
He cannot give it a place, any more than he can 
give a place to melancholy or joy ; nor can he con- 
ceive it to have any existence, but when it is smelled. 
So that it appears to be a simple and original 
affection or feeling of the mind, altogether inex- 
plicable and unaccountable. It is, indeed, impos- 
sible that it can be in any body : it is a sensation, 
and a sensation can only be in a sentient thing. 

The various odours have each their different 
degrees of strength or weakness. Most of them are 
agreeable or disagreeable ; and frequently those 
that are agreeable when weak, are disagreeable 
when stronger. When we compare different smells 
together, we can perceive very few resemblances 
or contrarieties, or, indeed, relations of any kind 
between them. They are all so simple in them- 
selves, and so different from each other, that it is 

REID 39 

hardly possible to divide them into genera and 
species. Most of the names we give them are parti- 
cular ; as the smell of a rose, of a jessamine, and 
the like. Yet there are some general names — as 
sweet, stinking, musty, putrid, cadaverous, aromatic. 
Some of them seem to refresh and animate the 
mind, others to deaden and depress it. 

§ 2. Sensation and Remembrance, Natural 
Principles of Belief 

So far we have considered this sensation ab- 
stractly. Let us next compare it with other things 
to which it bears some relation. And first I shall 
compare this sensation with the remembrance, and 
the imagination of it. 

I can think of the smell of a rose when I do not 
smell it ; and it is possible that when I think of it, 
there is neither rose nor smell anywhere existing. 
But when I smell it, I am necessarily determined to 
believe that the sensation really exists. This is 
common to all sensations, that, as they cannot exist 
but in being perceived, so they cannot be perceived 
but they must exist. I could as easily doubt of my 
own existence, as of the existence of my sensations. 
Even those profound philosophers who have en- 
deavoured to disprove their own existence, have yet 
left their sensations to stand upon their own bottom, 
stript of a subject, rather than call in question ^the 
reality of their existence. 


Here, then, a sensation, a smell for instance, 
may be presented to the mind three different ways : 
it may be smelled, it may be remembered, it may be 
imagined or thought of. In the first case, it is 
necessarily accompanied with a belief of its present 
existence ; in the second, it is necessarily accom- 
panied with a belief of its past existence ; and in 
the last, it is not accompanied with belief at all, 
but is what the logicians call a simple apprehension. 

Why sensation should compel our belief of the 
present existence of the thing, memory a belief of 
its past existence, and imagination no belief at all, 
I believe no philosopher can give a shadow of reason, 
but that such is the nature of these operations : 
they are all simple and original, and therefore 
inexplicable acts of the mind. 

Suppose that once, and only once, I smelled a 
tuberose in a certain room, where it grew in a pot, 
and gave a very grateful perfume. Next day I 
relate what I saw and smelled. When I attend as 
carefully as I can to what passes in my mind in this 
case, it appears evident that the very thing I saw 
yesterday, and the fragrance I smelled, are now 
the immediate objects of my mind, when I remember 
it. Further, I can imagine this pot and flower 
transported to the room where I now sit, and 
yielding the same perfume. Here likewise it 
appears, that the individual thing which I saw and 
smelled, is the object of my imagination. 

REID 41 

Philosophers indeed tell me, that the immediate 
object of my memory and imagination in this case, 
is not the past sensation, but an idea of it, an image, 
phantasm, or species, of the odour I smelled : that 
this idea now exists in my mind, or in my sensorium ; 
and the mind, contemplating this present idea, 
finds it a representation of what is past, or of what 
may exist; and accordingly calls it memory, or 
imagination. This is the doctrine of the ideal 
philosophy ; which we shall not now examine, that 
we may not interrupt the thread of the present in- 
vestigation. Upon the strictest attention, memory 
appears to me to have things that are past, and not 
present ideas, for its object. We shall afterwards 
examine this system of ideas, and endeavour 
to make it appear, that no soHd proof has ever 
been advanced of the existence of ideas ; that they 
are a mere fiction and hypothesis, contrived to 
solve the phaenomena of the human understand- 
ing ; that they do not at all answer this end ; and 
that this hypothesis of ideas or images of things 
in the mind, or in the sensorium, is the parent of 
those many paradoxes so shocking to common 
sense, and of that scepticism which disgrace our 
philosophy of the mind, and have brought upon it 
the ridicule and contempt of sensible men. 

In the meantime, I beg leave to think, with the 
vulgar, that, when I remember the smell of the 
tuberose, that very sensation which I had yesterday, 


and which has now no more any existence, is the 
immediate object of my memory ; and when I 
imagine it present, the sensation itself, and not any 
idea of it, is the object of my imagination. But, 
though the object of my sensation, memory, and 
imagination, be in this case the same, yet these 
acts or operations of the mind are as different, and 
as easily distinguishable, as smell, taste, and sound. 
I am conscious of a difference in kind between 
sensation and memory, and between both and 
imagination. I find this also, that the sensation 
compels my belief of the present existence of the 
smell, and memory my belief of its past existence. 
There is a smell, is the immediate testimony of 
sense ; there was a smell, is the immediate testimony 
of memory. If you ask me, why I believe that the 
smell exists, I can give no other reason, nor shall 
ever be able to give any other, than that I smell it. 
If you ask, why I believe that it existed yesterday, 
I can give no other reason but that I remember it. 

Sensation and memory, therefore, are simple, 
original, and perfectly distinct operations of the 
mind, and both of them are original principles of 
belief. Imagination is distinct from both, but is no 
principle of belief. Sensation implies the present 
existence of its object, memory its past existence, 
but imagination views its object naked, and without 
any belief of its existence or non-existence, and is 
therefore what the schools call Simple Apprehension. 

REID 43 

§ 3. Judgment and Belief in some Cases precede 
Simple Apprehension 

But here, again, the ideal system comes in our 
way : it teaches us that the first operation of the 
mind about its ideas, is simple apprehension — that 
is, the bare conception of a thing without any 
belief about it : and that, after we have got simple 
apprehensions, by comparing them together, we 
perceive agreements or disagreements between 
them ; and that this perception of the agreement 
or disagreement of ideas is all that we call belief, 
judgment, or knowledge. Now, this appears to 
me to be all fiction, without any foundation in 
nature ; for it is acknowledged by all, that sensation 
must go before memory and imagination ; and 
hence it necessarily follows, that apprehension, 
accompanied with belief and knowledge, must go 
before simple apprehension, at least in the matters 
we are now speaking of. So that here, instead of 
saying that the belief or knowledge is got by putting 
together and comparing the simple apprehensions, 
we ought rather to say that the simple apprehension 
is performed by resolving and analysing a natural 
and original judgment. And it is with the opera- 
tions of the mind, in this case, as with natural 
bodies, which are, indeed, compounded of simple 
principles or elements. Nature does not exhibit 
these elements separate, to be compounded by us ; 


she exhibits them mixed and compounded in 
concrete bodies, and it is only by art and chemical 
analysis that they can be separated. 

§ 4. Two Theories of the Nature of Belief 
Refuted — Conclusions from what hath 
been said 

But what is this belief or knowledge which accom- 
panies sensation and memory ? Every man knows 
what it is, but no man can define it. Does any man 
pretend to define sensation, or to define conscious- 
ness ? It is happy, indeed, that no man does. 
And if no philosopher had endeavoured to define 
and explain belief, some paradoxes in philosophy, 
more incredible than ever were brought forth by 
the most abject superstition or the most frantic 
enthusiasm, had never seen the light. Of this kind 
surely is that modern discovery of the ideal philo- 
sophy, that sensation, memory, belief, and imagina- 
tion, when they have the same object, are only 
different degrees of strength and vivacity in the 
idea. Suppose the idea to be that of a future state 
after death : one man believes it firmly — this means 
no more than that he hath a strong and lively idea 
of it ; another neither believes nor disbelieves — 
that is, he has a weak and faint idea. Suppose, 
now, a third person believes firmly that there is no 
such thing, I am at a loss to know whether his idea 
be faint or lively : if it is faint, then there may be a 

REID 45 

firm belief where the idea is faint ; if the idea is 
hvely, then the belief of a future state and the belief 
of no future state must be one and the same. The 
same arguments that are used to prove that belief 
implies only a stronger idea of the object than simple 
apprehension, might as well be used to prove that 
love implies only a stronger idea of the object than 
indifference. And then what shall we say of 
hatred, which must upon this hypothesis be a degree 
of love, or a degree of indifference ? If it should 
be said, that in love there is something more than 
an idea — to wit, an affection of the mind — may it 
not be said with equal reason, that in belief there is 
something more than an idea — to wit, an assent or 
persuasion of the mind ? 

But perhaps it may be thought as ridiculous to 
argue against this strange opinion, as to maintain it. 
Indeed, if a man should maintain that a circle, a 
square, and a triangle differ only in magnitude, and 
not in figure, I believe he would find nobody disposed 
either to believe him or to argue against him ; and 
yet I do not think it less shocking to common sense, 
to maintain that sensation, memory, and imagina- 
tion differ only in degree, and not in kind. I know 
it is said, that, in a delirium, or in dreaming, men 
are apt to mistake one for the other. But does it 
follow from this, that men who are neither dreaming 
nor in a delirium cannot distinguish them ? But 
Jiow does a man know that he is not in a delirium ? 


I cannot tell : neither can I tell how a man knows 
that he exists. But, if any man seriously doubts 
whether he is in a delirium, I think it highly pro- 
bable that he is, and that it is time to seek for a 
cure, which I am persuaded he will not find in 
the whole system of logic. 

I mentioned before Locke's notion of belief or 
knowledge ; he holds that it consists in a perception 
of the agreement or disagreement of ideas ; and 
this he values himself upon as a very important 

We shall have occasion afterwards to examine 
more particularly this grand principle of Locke's 
philosophy, and to shew that it is one of the main 
pillars of modern scepticism, although he had no 
intention to make that use of it. At present 
let us only consider how it agrees with the instances 
of belief now under consideration ; and whether 
it gives any light to them. I believe that the 
sensation I have exists ; and that the sensation 
I remember does not now exist, but did exist 
yesterday. Here, according to Locke's system, I 
compare the idea of a sensation with the ideas of 
past and present existence : at one time I perceive 
that this idea agrees with that of present existence, 
but disagrees with that of past existence ; but, at 
another time, it agrees with the idea of past 
existence, and disagrees with that of present exist- 
ence. Truly these ideas seem to be very capri- 

REID 47 

cious in their agreements and disagreements. 
Besides, I cannot, for my heart, conceive what is 
meant by either. I say a sensation exists, and I 
think I understand clearly what I mean. But you 
want to make the thing clearer, and for that end 
tell me, that there is an agreement between the 
idea of that sensation and the idea of existence. To 
speak freely, this conveys to me no light, but 
darkness ; I can conceive no otherwise of it, than 
as an odd and obscure circumlocution. I conclude, 
then, that the belief which accompanies sensation 
and memory, is a simple act of the mind, which 
cannot be defined. It is, in this respect, like seeing 
and hearing, which can never be so defined as to be 
understood by those who have not these faculties ; 
and to such as have them, no definition can make 
these operations more clear than they are already. 
In like manner, every man that has any belief 
— and he must be a curiosity that has none — 
knows perfectly what belief is, but can never de- 
fine or explain it. I conclude, also, that sensation, 
memory, and imagination, even where they have 
the same object, are operations of a quite different 
nature, and perfectly distinguishable by those who 
are sound and sober. A man that is in danger of 
confounding them, is indeed to be pitied ; but 
whatever relief he may find from another art, he 
can find none from logic or metaphysic. I conclude 
further, that it is no less a part of the human 


constitution, to believe the present existence of 
our sensations, and to believe the past existence of 
what we remember, than it is to believe that twice 
two make four. The evidence of sense, the evi- 
dence of memory, and the evidence of the necessary 
relations of things, are all distinct and original kinds 
of evidence, equally grounded on our constitution : 
none of them depends upon, or can be resolved into 
another. To reason against any of these kinds of 
evidence is absurd; nay, to reason for them is absurd. 
They are first principles ; and such fall not within 
the province of reason, but of common sense. 

§ 5." Apology for Metaphysical Absurdities — 
Sensation without a Sentient, a Conse- 
quence OF THE Theory of Ideas — Con- 
sequences OF this Strange Opinion 

Having considered the relation which the sensa- 
tion of smelling bears to the remembrance and 
imagination of it, I proceed to consider what 
relation it bears to a mind, or sentient principle. 
It is certain, no man can conceive or believe smelling 
to exist of itself, without a mind, or something that 
has the power of smelling, of which it is called a 
sensation, an operation, or feeling. Yet, if any man 
should demand a proof that sensation cannot be 
without a mind or sentient being, I confess that I 
can give none ; and that to pretend to prove it, 
seems to me almost as absurd as to deny it. 

REID 49 

This might have been said without any apology 
before the Treatise of Human Nature appeared in 
the world. For till that time, no man, as far as I 
know, ever thought either of calling in question that 
principle, or of giving a reason for his belief of it. 
Whether thinking beings were of an ethereal or 
igneous nature, whether material or immaterial, was 
variously disputed ; but that thinking is an opera- 
tion of some kind of being or other, was always 
taken for granted, as a principle that could not 
possibly admit of doubt. 

However, since the author above mentioned, who 
is undoubtedly one of the most acute metaphysicians 
that this or any other age hath produced, hath 
treated it as a vulgar prejudice, and maintained 
that the mind is only a succession of ideas and 
impressions without any subject ; his opinion, 
however contrary to the common apprehensions of 
mankind, deserves respect. I beg therefore, once 
for all, that no offence may be taken at charging 
this or other metaphysical notions with absurdity, 
or with being contrary to the common sense of 
mankind. No disparagement is meant to the under- 
standings of the authors or maintainers of such 
opinions. Indeed, they commonly proceed, not 
from defect of understanding, but from an excess 
of refinement; the reasoning that leads to them 
often gives new light to the subject, and shews 
real genius and deep penetration in the author; 



and the premises do more than atone for the 

If there are certain principles, as I think there are, 
which the constitution of our nature leads us to 
believe, and of which we are under a necessity to 
take for granted in the common concerns of life, 
without being able to give a reason for them — these 
are what we call the principles of common sense ; 
and what is manifestly contrary to them, is what 
we call absurd. 

Indeed, if it is true, and to be received as a 
principle of philosophy, that sensation and thought 
may be without a thinking being, it must be 
acknowledged to be the most wonderful discovery 
that this or any other age hath produced. The 
received doctrine of ideas is the principle from which 
it is deduced, and of which indeed it seems to be a 
just and natural consequence. And it is probable, 
that it would not have been so late a discovery, but 
that it is so shocking and repugnant to the common 
apprehensions of mankind, that it required an un- 
common degree of philosophical intrepidity to usher 
it into the world. It is a fundamental principle of 
the ideal system, that every object of thought must 
be an impression or an idea — that is, a faint copy 
of some preceding impression. This is a principle 
so commonly received, that the author above 
mentioned, although his whole system is built upon 
it, never offers the least proof of it. It is upon this 

REID 51 

principle, as a fixed point, that he erects his meta- 
physical engines, to overturn heaven and earth, 
body and spirit. And, indeed, in my apprehension, 
it is altogether sufficient for the purpose. For, if im- 
pressions and ideas are the only objects of thought, 
then heaven and earth, and body and spirit, and 
everything you please, must signify only impres- 
sions and ideas, or they must be words without 
any meaning. It seems, therefore, that this 
notion, however strange, is closely connected with 
the received doctrine of ideas, and we must 
either admit the conclusion, or call in question 
the premises. 

Ideas seem to have something in their nature 
unfriendly to other existences. They were first 
introduced into philosophy, in the humble character 
of images or representatives of things ; and in this 
character they seemed not only to be inoffensive, 
but to serve admirably well for explaining the 
operations of the human understanding. But, 
since men began to reason clearly and distinctly 
about them, they have by degrees supplanted their 
constituents, and undermined the existence of 
everything but themselves. First, they discarded 
all secondary qualities of bodies ; and it was found 
out by their means, that fire is not hot, nor snow 
cold, nor honey sweet ; and, in a word, that heat 
and cold, sound, colour, taste, and smell, are nothing 
but ideas or impressions. Bishop Berkeley ad- 


vanced them a step higher, and found out, by just 
reasoning from the same principles, that extension, 
solidity, space, figure, and body, are ideas, and that 
there is nothing in nature but ideas and spirits. 
But the triumph of ideas was completed by the 
Treatise of Human Nature, which discards spirits 
also, and leaves ideas and impressions as the 
sole existences in the universe. What if, at last, 
having nothing else to contend with, they should 
fall foul of one another, and leave no existence in 
nature at all ? This would surely bring philosophy 
into danger ; for what should we have left to talk 
or to dispute about ? 

However, hitherto these philosophers acknow- 
ledge the existence of impressions and ideas ; they 
acknowledge certain laws of attraction, or rules of 
precedence, according to which, ideas and im- 
pressions range themselves in various forms, and 
succeed one another : but that they should belong 
to a mind, as its proper goods and chattels, this they 
have found to be a vulgar error. These ideas are 
as free and independejnt as the birds of the air, or 
as Epicurus's atoms when they pursued their 
journey in the vast inane. Shall we conceive them 
like the films of things in the Epicurean system ? 

Principio hoc dico, rerum simulacra vagari, 
Multa modis multis, in cunctas undique parteis 
Tenuia, quae facile inter se junguntur in auris, 
Obvia cum veniunt. — LucR. 

REID 53 

Or do they rather resemble Aristotle's intelligible 
species, after they are shot forth from the object, 
and before they have yet struck upon the passive 
intellect ? But why should we seek to compare 
them with anything, since there is nothing in nature 
but themselves ? They make up the whole furni- 
ture of the universe ; starting into existence, or out 
of it, without any cause ; combining into parcels, 
which the vulgar call minds ; and succeeding one 
another by fixed laws, without time, place, or 
author of those laws. 

Yet, after all, these self-existent and independent 
ideas look pitifully naked and destitute, when left 
thus alone in the universe, and seem, upon the whole, 
to be in a worse condition than they were before. 
Des Cartes, Malebranche, and Locke, as they made 
much use of ideas, treated them handsomely, and 
provided them in decent accommodation ; lodging 
them either in the pineal gland, or in the pure 
intellect, or even in the divine mind. They more- 
over clothed them with a commission, and made 
them representatives of things, which gave them 
some dignity and character. But the Treatise of 
Human Nature, though no less indebted to them, 
seems to have made but a bad return, by bestow- 
ing upon them this independent existence ; since 
thereby they are turned out of house and home, and 
set adrift in the world, without friend or connection, 
without a rag to cover their nakedness ; and who 


knows but the whole system of ideas may perish 
by the indiscreet zeal of their friends to exalt 
them ? 

However this may be, it is certainly a most 
amazing discovery that thought and ideas may be 
without any thinking being — a discovery big with 
consequences which cannot easily be traced by 
those deluded mortals who think and reason in 
the common track. We were always apt to 
imagine, that thought supposed a thinker, and 
love a lover, and treason a traitor : but this, it 
seems, was all a mistake ; and it is found out that 
there may be treason without a traitor, and love 
without a lover, laws without a legislator, and 
punishment without a sufferer, succession without 
time, and motion without anything moved, or 
space in which it may move : or if, in these cases, 
ideas are the lover, the sufferer, the traitor, it were 
to be wished that the author of this discovery had 
farther condescended to acquaint us whether ideas 
can converse together, and be under obligations 
of duty or gratitude to each other ; whether they 
can makf promises and enter into leagues and 
covenants, and fulfil or break them, and be punished 
for the breach. If one set of ideas makes a covenant, 
another breaks it, and a third is punished for it, 
there is reason to think that justice is no natural 
virtue in this system. 

It seemed very natural to think that the Treatise 

REID 55 

of Human Nature required an author, and a very 
ingenious one too ; but now we learn that it is only 
a set of ideas which came together and arranged 
themselves by certain associations and attractions. 

After all, this curious system appears not to be 
fitted to the present state of human nature. How 
far it may suit some choice spirits, who are refined 
from the dregs of common sense, I cannot say. It 
is acknowledged, I think, that even these can enter 
into this system only in their most speculative 
hours, when they soar so high in pursuit of those 
self-existent ideas as to lose sight of all other things. 
But when they condescend to mingle again with the 
human race, and to converse with a friend, a com- 
panion, or a fellow-citizen, the ideal system vanishes ; 
common sense, like an irresistible torrent, carries 
them along ; and, in spite of all their reasoning and 
philosophy, they believe their own existence, and 
the existence of other things. 

Indeed, it is happy they do so ; for, if they should 
carry their closet belief into the world, the rest 
of mankind would consider them as diseased, 
and send them to an infirmary. Therefore, as 
Plato required certain previous qualifications of 
those who entered his school, I think it would be 
prudent for the doctors of this ideal philosophy 
to do the same, and to refuse admittance to every 
man who is so weak as to imagine that he ought to 
have the same belief in solitude and in company. 


or that his principles ought to have any influence 
upon his practice ; for this philosophy is like a 
hobby-horse, which a man in bad health may ride 
in his closet, without hurting his reputation ; but, 
if he should take him abroad with him to church, 
or to the exchange, or to the play-house, his heir 
would immediately call a jury, and seize his estate. 

§6. The Conception and Belief of a Sentient 
Being or Mind is suggested by our Con- 
stitution — The Notion of Relations not 
always got by comparing the related 

Leaving this philosophy, therefore, to those who 
have occasion for it, and can use it discreetly as a 
chamber exercise, we may still inquire how the 
rest of mankind, 'and even the adepts themselves, 
except in some solitary moments, have got so 
strong and irresistible a belief, that thought must 
have a subject, and be the act of some thinking 
being ; how every man believes himself to be some- 
thing distinct from his ideas and impressions — some- 
thing which continues the same identical self when all 
his ideas and impressions are changed. It is impos- 
sible to trace the origin of this opinion in history; for 
all languages have it interwoven in their original con- 
struction. All nations have always believed it. The 
constitution of all laws and governments, as well as 
the common transactions of life, suppose it. 

REID 57 

It is no less impossible for any man to recollect 
when he himself came by this notion ; for, as far 
back as we can remember, we were already in 
possession of it, and as fully persuaded of our own 
existence, and the existence of other things, as that 
one and one make two. It seems, therefore, that 
this opinion preceded all reasoning, and experience, 
and instruction ; and this is the more probable, 
because we could not get it by any of these means. 
It appears, then, to be an undeniable fact, that, 
from thought or sensation, all mankind, constantly 
and invariably, from the first dawning of reflection, 
do infer a power or faculty of thinking, and a per- 
manent being or mind to which that faculty belongs ; 
and that we as invariably ascribe all the various 
kinds of sensation and thought we are conscious 
of, to one individual mind or self. 

But by what rules of logic we make these infer- 
ences, it is impossible to shew ; nay, it is impossible 
to shew how our sensations and thoughts can give 
us the very notion and conception either of a mind 
or of a faculty. The faculty of smelling is some- 
thing very different from the actual sensation of 
smelling ; for the faculty may remain when we have 
no sensation. And the mind is no less different 
from the faculty ; for it continues the same in- 
dividual being when that faculty is lost. Yet 
this sensation suggests to us both a faculty and a 
mind ; and not only suggests the notion of them, 


but creates a belief of their existence ; although 
it is impossible to discover, by reason, any tie or 
connection between one and the other. 

What shall we say, then ? Either those infer- 
ences which we draw from our sensations — namely, 
the existence of a mind, and of powers or faculties 
belonging to it — are prejudices of philosophy or 
education, mere fictions of the mind, which a wise 
man should throw off as he does the belief of fairies ; 
or they are judgments of nature — judgments not 
got by comparing ideas, and perceiving agreements 
and disagreements, but immediately inspired by 
our constitution. 

If this last is the case, as I apprehend it is, it will 
be impossible to shake off those opinions, and we 
must yield to them at last, though we struggle hard 
to get rid of them. And if we could, by a deter- 
mined obstinacy, shake off the principles of our 
nature, this is not to act the philosopher, but the 
fool or the madman. It is incumbent upon those 
who think that these are not natural principles, to 
shew, in the first place, how we can otherwise get 
the notion of a mind and its faculties ; and then to 
shew how we come to deceive ourselves into the 
opinion that sensation cannot be without a sentient 

It is the received doctrine of philosophers, that 
our notions of relations can only be got by com- 
paring the related ideas : but, in the present case. 

REID 59 

there seems to be an instance to the contrary. It 
is not by having first the notions of mind and sensa- 
tion, and then comparing them together, that we 
perceive the one to have the relation of a subject 
or substratum, and the other that of an act or 
operation : on the contrary, one of the related things 
— to wit, sensation — suggests to us both the corre- 
late and the relation. 

I beg leave to make use of the word suggestion, 
because I know not one more proper, to express 
a power of the mind, which seems entirely to have 
escaped the notice of philosophers, and to which we 
owe many of our simple notions which are neither 
impressions nor ideas, as well as many original 
principles of belief. I shall endeavour to illustrate, 
by an example, what I understand by this word. 
We all know, that a certain kind of sound suggests 
immediately to the mind, a coach passing in the 
street ; and not only produces the imagination, but 
the belief, that a coach is passing. Yet there is 
here no comparing of ideas, no perception of agree- 
ments or disagreements, to produce this belief ; 
nor is there the least similitude between the sound 
we hear and the coach we imagine and believe to 
be passing. 

It is true that this suggestion is not natural and 
original ; it is the result of experience and habit. 
But I think it appears, from what hath been said, 
fhat there are natural suggestions : particularly. 


that sensation suggests the notion of present 
existence, and the belief that what we perceive 
or feel does now exist ; that memory suggests the 
notion of past existence, and the belief that what 
we remember did exist in time past ; and that our 
sensations and thoughts do also suggest the notion 
of a mind, and the belief of its existence, and of 
its relation to our thoughts. By a like natural 
principle it is, that a beginning of existence, or any 
change in nature, suggests to us the notion of a cause 
and compels our belief of its existence. And, in 
like manner, as shall be shewn when we come to 
the sense of touch, certain sensations of touch, by 
the constitution of our nature, suggest to us exten- 
sion, solidity, and motion, which are nowise like 
to sensations, although they have been hitherto 
confounded with them. 

§7. There is a Quality or Virtue in Bodies, 


connected in the imagination with the 

We have considered smell as signifying a sensa- 
tion, feeling, or impression upon the mind ; and in 
this sense, it can only be in a mind, or sentient 
being : but it is evident that mankind give the name 
of smell much more frequently to something which 
they conceive to be external, and to be a quality 
of body : they understand something by it which 

REID 6i 

does not at all infer a mind ; and have not the least 
difficulty in conceiving the air perfumed with aro- 
matic odours in the deserts of Arabia, or in some 
uninhabited island, where the human foot never 
trod. Every sensible day-labourer hath as clear 
a notion of this, and as full a conviction of the 
possibility of it, as he hath of his own existence ; 
and can no more doubt of the one than of the other. 
Suppose that such a man meets with a modern 
philosopher, and wants to be informed what smell 
in plants is. The philosopher tells him, that there 
is no smell in plants, nor in anything but in the 
mind ; that it is impossible there can be smell but in 
a mind ; and that all this hath been demonstrated 
by modern philosophy. The plain man will, no 
doubt, be apt to think him merry : but, if he finds 
that he is serious, his next conclusion will be that 
he is mad ; or that philosophy, like magic,, puts 
men into a new world, and gives them different 
faculties from common men. And thus philosophy 
and common sense are set at variance. But who 
is to blame for it ? In my opinion the philosopher 
is to blame. For if he means by smell, what the 
rest of mankind most commonly mean, he is 
certainly mad. But if he puts a different meaning 
upon the word, without observing it himself, or 
giving warning to others, he abuses language and 
disgraces philosophy, without doing any service 
to truth : as if a man should exchange the meaning 


of the words daughter and cow, and then endeavour 
to prove to his plain neighbour, that his cow is his 
daughter, and his daughter his cow. 

I believe there is not much more wisdom in many 
of those paradoxes of the ideal philosophy, which to 
plain sensible men appear to be palpable absurdities, 
but with the adepts pass for profound discoveries. I 
resolve, for my own part, always to pay a great regard 
to the dictates of common sense, and not to depart 
from them without absolute necessity : and, there- 
fore, I am apt to think that there is really something 
in the rose or lily, which is by the vulgar called 
smell, and which continues to exist when it is not 
smelled : and shall proceed to inquire what this is ; 
how we come by the notion of it ; and what relation 
this quality or virtue of smell hath to the sensation 
which we have been obliged to call by the same 
name, for want of another. 

Let us therefore suppose, as before, a person 
beginning to exercise the sense of smelling ; a little 
experience will discover to him, that the nose is the 
organ of this sense, and that the air, or something 
in the air, is a medium of it. And finding, by 
farther experience, that, when a rose is near, he has 
a certain sensation, when it is removed, the sensa- 
tion is gone, he finds a connection in nature betwixt 
the rose and this sensation. The rose is considered 
as a cause, occasion, or antecedent of the sensation ; 
the sensation as an effect or consequence of the 

REID 63 

presence of the rose ; they are associated in the 
mind, and constantly found conjoined in the 

But here it deserves our notice, that, although 
the sensation may seem more closely related to the 
mind its subject, or to the nose its organ, yet 
neither of these connections operate so powerfully 
upon the imagination as its connection with the 
rose its concomitant. The reason of this seems 
to be, that its connection with the mind is more 
general, and noway distinguisheth it from other 
smells, or even from tastes, sounds, and other kinds 
of sensations. The relation it hath to the organ 
is likewise general, and doth not distinguish it from 
other smells ; but the connection it hath with the 
rose is special and constant ; by which means they 
become almost inseparable in the imagination, in 
like manner as thunder and lightning, freezing 
and cold. 

§ 8. That there is a Principle in Human Nature, 


In order to illustrate further how we come to 
conceive a quality or virtue in the rose which we 
call smell, and what this smell is, it is proper to 
observe, that the mind begins very early to thirst 
after principles which may direct it in the exertion 


of its powers. The smell of a rose is a certain 
affection or feeling of the mind ; and, as it is not 
constant, but comes and goes, we want to know 
when and where we may expect it ; and are uneasy 
till we find something which, being present, brings 
this feeling along with it, and, being removed, 
removes it. This, when found, we call the cause of 
it ; not in a strict and philosophical sense, as if the 
feeling were really effected or produced by that 
cause, but in a popular sense ; for the mind is 
satisfied if there is a constant conjunction between 
them ; and such causes are in reality nothing else 
but laws of nature. Having found the smell thus 
constantly conjoined with the rose, the mind is at 
rest, without inquiring whether this conjunction 
is owing to a real efficiency or not ; that being a 
philosophical inquiry, which does not concern 
human life. But every discovery of such a con- 
stant conjunction is of real importance in life, and 
makes a strong impression upon the mind. 

So ardently do we desire to find everything that 
happens within our observation thus connected 
with something else as its cause or occasion, that 
we are apt to fancy connections upon the slightest 
grounds ; and this weakness is most remarkable 
in the ignorant, who know least of the real connec- 
tions established in nature. A man meets with an 
unlucky accident on a certain day of the year, and, 
knowing no other cause of his misfortune, he is apt 

REID 65 

to conceive something unlucky in that day of the 
calendar ; and, if he finds the same connection 
hold a second time, is strongly confirmed in his 
superstition. I remember, many years ago, a 
white ox was brought into this country, of so 
enormous a size that people came many miles to 
see him. There happened, some months after, an 
uncommon fatality among women in child-bearing. 
Two such uncommon events, following one another, 
gave a suspicion of their connection, and occasioned 
a common opinion among the country-people that 
the white ox was the cause of this fatality. 

However silly and ridiculous this opinion was, 
it sprung from the same root in human nature on 
which all natural philosophy grows — namely, an 
eager desire to find out connections in things, and 
a natural, original, and unaccountable propensity 
to believe that the connections which we have ob- 
served in time past will continue in time to come. 
Omens, portents, good and bad luck, palmistry, 
astrology, all the numerous arts of divination and of 
interpreting dreams, false hypotheses and systems, 
and true principles in the philosophy of nature, are 
all built upon the same foundation in the human 
constitution, and are distinguished only according 
as we conclude rashly from too few instances, or 
cautiously from a sufficient induction. 

As it is experience only that discovers these con- 
nections between natural causes and their effects ; 



without inquiring further, we attribute to the cause 
some vague and indistinct notion of power or virtue 
to produce the effect. And, in many cases, the 
purposes of Hfe do not make it necessary to give 
distinct names to the cause and the effect. Whence 
it happens, that, being closely connected in the 
imagination, although very unlike to each other, 
one name serves for both ; and, in common discourse, 
is most frequently applied to that which, of the two, 
is most the object of our attention. This occasions 
an ambiguity in many words, which, having the 
same causes in all languages, is common to all, and 
is apt to be overlooked even by philosophers. Some 
instances will serve both to illustrate and confirm 
what we have said. 

Magnetism signifies both the tendency of the 
iron towards the magnet, and the power of the 
magnet to produce that tendency ; and, if it was 
asked, whether it is a quality of the iron or of the 
magnet, one would perhaps be puzzled at first ; but 
a little attention would discover, that we conceive 
a power or virtue in the magnet as the cause, and 
a motion in the iron as the effect ; and, although 
these are things quite unlike, they are so united 
in the imagination, that we give the common name 
of magnetism to both. The same thing may be said 
of gravitation, which sometimes signifies the tend- 
ency of bodies towards the earth, sometimes the 
attractive power of the earth, which we conceive 

REID 67 

as the cause of that tendency. We may observe 
the same ambiguity in some of Sir Isaac Newton's 
definitions ; and that even in words of his own 
making. In three of his definitions, he explains 
very distinctly what he understands by the absolute 
quantity, what by the accelerative quantity, and 
what by the motive quantity, of a centripetal force. 
In the first of these three definitions, centripetal 
force is put for the cause, which we conceive to be 
some power or virtue in the centre or central body ; 
in the last two, the same word is put for the effect 
of this cause, in producing velocity, or in producing 
motion towards that centre. 

Heat signifies a sensation, and cold a contrary one ; 
but heat likewise signifies a quality or state of bodies, 
which hath no contrary, but different degrees. 
When a man feels the same water hot to one hand 
and cold to the other, this gives him occasion to 
distinguish between the feeling and the heat of the 
body ; and, although he knows that the sensations 
are contrary, he does not imagine that the body 
can have contrary qualities at the same time. And 
when he finds a different taste in the same body in 
sickness and in health, he is easily convinced that 
the quality in the body called taste is the same as 
before, although the sensations he has from it are 
perhaps opposite. 

The vulgar are commonly charged by philo- 
sophers, with the absurdity of imagining the smell 


in the rose to be something like to the sensation of 
smelling ; but I think unjustly ; for they neither 
give the same epithets to both, nor do they reason 
in the same manner from them. What is smell in 
the rose ? It is a quality or virtue of the rose, or 
of something proceeding from it, which we perceive 
by the sense of smelling ; and this is all we know 
of the matter. But what is smelling ? It is an 
act of the mind, but is never imagined to be a 
quality of the mind. Again, the sensation of 
smelling is conceived to infer necessarily a mind 
or sentient being ; but smell in the rose infers no 
such thing. We say, this body smells sweet, that 
stinks ; but we do not say, this mind smells sweet 
and that stinks. Therefore, smell in the rose, and 
the sensation which it causes, are not conceived, 
even by the vulgar, to be things of the same kind, 
although they have the same name. 

From what hath been said, we may learn that the 
smell of a rose signifies two things : First, a sensa- 
tion, which can have no existence but when it is 
perceived, and can only be in a sentient being or 
mind ; Secondly, it signifies some power, quality, 
or virtue, in the rose, or in efiluvia proceeding from 
it, which hath a permanent existence, independent 
of the mind, and which, by the constitution of 
nature, produces the sensation in us. By the 
original constitution of our nature, we are both led 
to believe that there is a permanent cause of the 

REID 69 

sensation, and prompted to seek after it ; and 
experience determines us to place it in the rose. 
The names of all smells, tastes, sounds, as well as 
heat and cold, have a like ambiguity in all languages; 
but it deserves our attention, that these names are 
but rarely, in common language, used to signify 
the sensations ; for the most part, they signify 
the external qualities which are indicated by the 
sensations — the cause of which phaenomenon I take 
to be this. Our sensations have very different 
degrees of strength. Some of them are so quick 
and lively as to give us a great deal either of pleasure 
or of uneasiness. When this is the case, we are 
compelled to attend to the sensation itself, and to 
make it an object of thought and discourse ; we 
give it a name, which signifies nothing but the 
sensation ; and in this case we readily acknowledge 
that the thing meant by that name is in the mind 
only, and not in anything external. Such are the 
various kinds of pain, sickness, and the sensations 
of hunger and other appetites. But, where the 
sensation is not so interesting as to require to be 
made an object of thought, our constitution leads 
us to consider it as a sign of something external, 
which hath a constant conjunction with it ; and, 
having found what it indicates, we give a name to 
that : the sensation, having no proper name, falls 
in as an accessory to the thing signified by it, and 
is confounded under the same name. So that the 


name may, indeed, be applied to the sensation, but 
most properly and commonly is applied to the thing 
indicated by that sensation. The sensations of 
smell, taste, sound, and colour, are of infinitely more 
importance as signs or indications, than they are 
upon their own account ; like the words of a 
language, wherein we do not attend to the sound 
but to the sense. 

§ 9. Whether in Sensation the Mind is Active 
OR Passive ? 

There is one inquiry remains. Whether, in 
smelling, and in other sensations, the mind is active 
or passive ? This possibly may seem to be a 
question about words, or, at least, of very small 
importance ; however, if it leads us to attend more 
accurately to the operations of our minds than we 
are accustomed to do, it is, upon that very account, 
not altogether unprofitable. I think the opinion 
of modern philosophers is, that in sensation the 
mind is altogether passive. And this undoubtedly 
is so far true, that we cannot raise any sensation in 
our minds by willing it ; and, on the other hand, it 
seems hardly possible to avoid having the sensation 
when the object is presented. Yet it seems likewise 
to be true, that, in proportion as the attention is 
more or less turned to a sensation or diverted from 
it, that sensation is more or less perceived and 
remembered. Every one knows that very intense 

REID 71 

pain may be diverted by a surprise, or by anything 
that entirely occupies the mind. When we are 
engaged in earnest conversation, the clock may 
strike by us without being heard ; at least, we 
remember not, the next moment, that we did hear 
it. The noise and tumult of a great trading city 
is not heard by them who have lived in it all their 
days ; but it stuns those strangers who have 
lived in the peaceful retirement of the country. 
Whether, therefore, there can be any sensation 
where the mind is purely passive, I will not say ; 
but I think we are conscious of having given some 
attention to every sensation which we remember, 
though ever so recent. 

No doubt, where the impulse is strong and un- 
common, it is as difficult to withhold attention 
as it is to forbear crying out in racking pain, or 
starting in a sudden fright. But how far both 
might be attained by strong resolution and practice, 
is not easy to determine. So that, although the 
Peripatetics had no good reason to suppose an 
active and a passive intellect, since attention may 
be well enough accounted an act of the will, yet I 
think they came nearer to the truth, in holding the 
mind to be in sensation partly passive and partly 
active, than the moderns, in affirming it to be 
purely passive. Sensation, imagination, memory, 
and judgment, have, by the vulgar in all ages, 
been considered as acts of the mind. The manner in 


which they are expressed in all languages shews 
this. When the mind is much employed in them, 
we say it is very active ; whereas, if they were 
impressions only, as the ideal philosophy would 
lead us to conceive, we ought, in such a case, rather 
to say, that the mind is very passive ; for, I sup- 
pose, no man would attribute great activity to the 
paper I write upon, because it receives variety of 

The relation which the sensation of smell bears to 
the memory and imagination of it, and to a mind or 
subject, is common to all our sensations, and, indeed, 
to all the operations of the mind ; the relation it 
bears to the will is common to it with all the powers 
of understanding ; and the relation it bears to that 
quality or virtue of bodies which it indicates, is 
common to it with the sensations of taste, heading, 
colour, heat, and cold — so that what hath been said 
of this sense, may easily be applied to several of 
our senses, and to other operations of the mind ; 
and this, I hope, will apologize for our insisting so 
long upon it.^ 

§ I. Of Hardness 

Hardness of bodies is a thing that we conceive 
as distinctly, and believe as firmly, as anything in 

* Ibid., pp. 105-115. 

REID 73 

nature. We have no way of coming at this con- 
ception and behef, but by means of a certain 
sensation of touch, to which hardness hath not the 
least similitude ; nor can we, by any rules of 
reasoning, infer the one from the other. The 
question is, How we come by this conception 
and belief ? 

First, as to the conception : Shall we call it an 
idea of sensation, or of reflection ? The last will 
not be affirmed ; and as little can the first, unless 
we will call that an idea of sensation which hath no 
resemblance to any sensation. So that the origin 
of this idea of hardness, one of the most common 
and most distinct we have, is not to be found in all 
our systems of the mind : not even in those which 
have so copiously endeavoured to deduce all our 
notions from sensation and reflection. 

But, secondly, supposing we have got the con- 
ception of hardness, how came we by the belief of it ? 
Is it self-evident, from comparing the ideas, that 
such a sensation could not be felt, unless such a 
quality of bodies existed ? No. Can it be proved 
by probable or certain arguments ? No ; it 
cannot. Have we got this belief, then, by tradition, 
by education, or by experience ? No ; it is not got 
in any of these ways. Shall we then throw off this 
belief as having no foundation in reason ? Alas ! 
it is not in our power ; it triumphs over reason, and 
laughs at all the arguments of a philosopher. Even 


the author of the Treatise of Human Nature, though 
he saw no reason for this behef, but many against 
it, could hardly conquer it in his speculative and 
solitary moments ; at other times, he fairly yielded 
to it, and confesses that he found himself under a 
necessity to do so. 

What shall we say, then, of this conception, and 
this belief, which are so unaccountable and un- 
tractable ? I see nothing left, but to conclude, 
that, by an original principle of our constitution, a 
certain sensation of touch both suggests to the mind 
the conception of hardness, and creates the belief 
of it : or, in other words, that this sensation is a 
natural sign of hardness. And this I shall en- 
deavour more fully to explain. 

§ 2. Of Natural Signs 

As in artificial signs there is often neither simili- 
tude between the sign and thing signified, nor any 
connection that arises necessarily from the nature 
of the things, so it is also in natural signs. The 
word gold has no similitude to the substance 
signified by it ; nor is it in its own nature more fit 
to signify this than any other substance ; yet, by 
habit and custom, it suggests this and no other. 
In like manner, a sensation of touch suggests hard- 
ness, although it hath neither similitude to hardness, 
nor, as far as we can perceive, any necessary con- 
nection with it. The difference betwixt these two 

REID 75 

signs lies only in this — that, in the first, the sug- 
gestion is the effect of habit and custom ; in the 
second, it is not the effect of habit, but of the 
original constitution of our minds. 

It appears evident from what hath been said on 
the subject of language, that there are natural signs 
as well as artificial ; and particularly, that the 
thoughts, purposes, and dispositions of the mind, 
have their natural signs in the features of the face, 
the modulation of the voice, and the motion and 
attitude of the body : that, without a natural 
knowledge of the connection between these signs 
and the things signified by them, language could 
never have been invented and established among 
men : and, that the fine arts are all founded 
upon this connection, which we may call the 
natural language of mankind. It is now proper 
to observe, that there are different orders of natural 
signs, and to point out the different classes into 
which they may be distinguished, that we may more 
distinctly conceive the relation between our sensa- 
tions and the things they suggest, and what we mean 
by calling sensations signs of external things. 

The first class of natural signs comprehends 
those whose connection with the thing signified 
is established by nature, but discovered only by 
experience. The whole of genuine philosophy 
consists in discovering such connections, and re- 
ducing them to general rules. The great Lord 


Verulam had a perfect comprehension of this, when 
he called it an interpretation of nature. No man 
ever more distinctly understood or happily expressed 
the nature and foundation of the philosophical 
art. What is all we know of mechanics, astronomy, 
and optics, but connections established by nature, 
and discovered by experience or observation, and 
consequences deduced from them ? All the know- 
ledge we have in agriculture, gardening, chemistry, 
and medicine, is built upon the same foundation. 
And if ever our philosophy concerning the human 
mind is carried so far as to deserve the name of 
science, which ought never to be despaired of, it 
must be by observing facts, reducing them to 
general rules, and drawing just conclusions from 
them. What we commonly call natural causes 
might, with more propriety, be called natural 
signs, and what we call effects, the things signified. 
The causes have no proper efficiency or causality, 
as far as we know ; and all we can certainly affirm 
is, that nature hath established a constant con- 
junction between them and the things called their 
effects ; and hath given to mankind a disposition 
to observe those connections, to confide in their 
continuance, and to make use of them for the 
improvement of our knowledge, and increase of 
our power. 

A second class is that wherein the connection 
between the sign and thing signified, is not only 

REID 77 

established by nature, but discovered to us by a 
natural principle, without reasoning or experience. 
Of this kind are the natural signs of human thoughts, 
purposes, and desires, which have been already 
mentioned as the natural language of mankind. 
An infant may be put into a fright by an angry 
countenance, and soothed again by smiles and 
blandishments. A child that has a good musical 
ear, may be put to sleep or to dance, may be 
made merry or sorrowful, by the modulation of 
musical sounds. The principles of all the fine arts, 
and of what we call a fine taste, may be resolved 
into connections of this kind. A fine taste may be 
improved by reasoning and experience ; but if the 
first principles of it were not planted in our minds 
by nature, it could never be acquired. Nay, we 
have already made it appear, that a great part of 
this knowledge which we have by nature, is lost 
by the disuse of natural signs, and the substitution 
of artificial in their place. 

A third class of natural signs comprehends 
those which, though we never before had any 
notion or conception of the thing signified, do 
suggest it, or conjure it up, as it were, by a natural 
kind of magic, and at once give us a conception and 
create a belief of it. I shewed formerly, that our 
sensations suggest to us a sentient being or mind 
to which they belong — a being which hath a per- 
manent existence, although the sensations are 


transient and of short duration — a being which is 
still the same, while its sensations and other 
operations are varied ten thousand ways — a being 
which hath the same relation to all that infinite 
variety of thoughts, purposes, actions, affections, 
enjoyments, and sufferings, which we are conscious 
of, or can remember. The conception of a mind 
is neither an idea of sensation nor of reflection ; 
for it is neither like any of our sensations, nor like 
anything we are conscious of. The first conception 
of it, as well as the behef of it, and of the common 
relation it bears to all that we are conscious of, or 
remember, is suggested to every thinking being, 
we do not know how. 

The notion of hardness in bodies, as well as the 
belief of it, are got in a similar manner ; being, by 
an original principle of our nature, annexed to 
that sensation which we have when we feel a hard 
body. And so naturally and necessarily does the 
sensation convey the notion and belief of hard- 
ness, that hitherto they have been confounded 
by the most acute inquirers into the principles 
of human nature, although they appear, upon 
accurate reflection, not only to be different 
things, but as unlike as pain is to the point 
of a sword. 

It may be observed, that, as the first class of 
natural signs I have mentioned is the foundation 
of true philosophy, and the second the foundation 

REID 79 

of the fine arts, or of taste — so the last is the 
foundation of common sense — a part of human 
nature which hath never been explained. 

I take it for granted, that the notion of hardness, 
and the belief of it, is first got by means of that 
particular sensation which, as far back as we can 
remember, does invariably suggest it; and that, if 
we had never had such a feeling, we should never 
have had any notion of hardness. I think it is 
evident, that we cannot, by reasoning from our 
sensations, collect the existence of bodies at all, far 
less any of their qualities. This hath been proved 
by unanswerable arguments by the Bishop of 
Cloyne, and by the author of the Treatise of Human 
Nature. It appears as evident that this connection 
between our sensations and the conception and 
belief of external existences cannot be produced 
by habit, experience, education, or any principle 
of human nature that hath been admitted by philo- 
sophers. At the same time, it is a fact that such 
sensations are invariably connected with the con- 
ception and belief of external existences. Hence, 
by all rules of just reasoning, we must conclude, 
that this connection is the effect of our con- 
stitution, and ought to be considered as an 
original principle of human nature, till we find 
some more general principle into which it may 
be resolved.^ 

1 Ibid., pp. I2I-I22. 


§ 3. Of Extension 

It is further to be observed, that hardness and 
softness, roughness and smoothness, figure and 
motion, do all suppose extension, and cannot be 
conceived without it ; yet, I think it must, on the 
other hand, be allowed that, if we had never felt 
any thing hard or soft, rough or smooth, figured 
or moved, we should never have had a conception 
of extension ; so that, as there is good ground 
to believe that the notion of extension could not 
be prior to that of other primary qualities, so it 
is certain that it could not be posterior to the 
notion of any of them, being necessarily implied in 
them all. 

Extension, therefore, seems to be a quality 
suggested to us, by the very same sensations which 
suggest the other qualities above mentioned. When 
I grasp a ball in my hand, I perceive it at once hard, 
figured, and extended. The feeling is very simple, 
and hath not the least resemblance to any quality 
of body. Yet it suggests to us three primary 
qualities perfectly distinct from one another, as 
well as from the sensation which indicates them. 
When I move my hand along the table, the feeling 
is so simple that, I find it difficult to distinguish 
it into things of different natures ; yet, it immedi- 
ately suggests hardness, smoothness, extension, and 
motion — things of very different natures, and all 

REID 8i 

of them as distinctly understood as the feehng 
which suggests them. 

We are commonly told by philosophers, that we 
get the idea of extension by feeling along the 
extremities of a body, as if there was no manner of 
difficulty in the matter. I have sought, with great 
pains, I confess, to find out how this idea can be 
got by feeling ; but I have sought in vain. Yet it 
is one of the clearest and most distinct notions 
we have ; nor is there anything whatsoever about 
which the human understanding can carry on so 
many long and demonstrative trains of reasoning. 

The notion of extension is so familiar to us from 
infancy, and so constantly obtruded by everything 
we see and feel, that we are apt to think it obvious 
how it comes into the mind ; but upon a narrower 
examination we shall find it utterly inexplicable. 
It is true we have feelings of touch, which every 
moment present extension to the mind ; but how 
they come to do so, is the question ; for those 
feelings do no more resemble extension than they 
resemble justice or courage — nor can the existence 
of extended things be inferred from those feelings 
by any rules of reasoning ; so that the feelings we 
have by touch, can neither explain how we get the 
notion, nor how we come by the belief of extended 

What hath imposed upon philosophers in this 

matter is, that the feelings of touch, which suggest 



primary qualities, have no names, nor are they ever 
reflected upon. They pass through the mind in- 
stantaneously, and serve only to introduce the 
notion and belief of external things, which, by our 
constitution, are connected with them. They are 
natural signs, and the mind immediately passes 
to the thing signified, without making the least 
reflection upon the sign, or observing that there was 
any such thing. Hence it hath always been taken 
for granted, that the ideas of extension, figure, and 
motion, are ideas of sensation, which enter into 
the mind by the sense of touch, in the same manner 
as the sensation of sound and smell do by the ear 
and nose. The sensations of touch are so con- 
nected, by our constitution, with the notions of 
extension, figure, and motion, that philosophers 
have mistaken the one for the other, and never 
have been able to discern that they were not only 
distinct things, but altogether unlike. However, 
if we will reason distinctly upon this subject, we 
ought to give names to those feelings of touch ; 
we must accustom cmrselves to attend to them, and 
to reflect upon them, that we may be able to disjoin 
them from, and to compare them with, the qualities 
signified or suggested by them. 

The habit of doing this is not to be attained with- 
out pains and practice ; and till a man hath acquired 
this habit, it will be impossible for him to think 
distinctly, or to judge right, upon this subject. 

REID 83 

Let a man press hi?, hand against the table — he 
feels it hard. But what is the meaning of this? 
— The meaning undoubtedly is, that he hath a 
certain feeling of touch, from which he concludes, 
without any reasoning, or comparing ideas, that 
there is something external really existing, whose 
parts stick so firmly together, 'that they cannot be 
displaced without considerable lorce. 

There is here a feeling, and a conclusion drawn 
from it, or some way suggested by it. In order 
to compare these, we must view them separately, 
and then consider by what tie they are connected, 
and wherein they resemble one another. The hard- 
ness of the table is the conclusion, the feeling is 
the medium by which we are led to that conclusion. 
Let a man attend distinctly to this medium, and to 
the conclusion, and he will perceive them to be as 
unlike as any two things in nature. The one is a 
sensation of the mind, which can have no existence 
but in a sentient being ; nor can it exist one moment 
longer than it is felt ; the other is in the table, and 
we conclude, without any difficulty, that it was in 
the table before it was felt, and continues after 
the feeling is over. The one implies no kind of 
extension, nor parts, nor cohesion ; the other 
implies all these. Both, indeed, admit of degrees, 
and the feeling, beyond a certain degree, is a species 
of pain ; but adamantine hardness does not imply 
the least pain. 


And as the feeling hath nG« similitude to hardness, 
so neither can our reason* perceive the least tie or 
connection between thtim ; nor will the logician 
ever be able to shew a reason why we should con- 
clude hardness from this feeling, rather than soft- 
ness, or any other quality whatsoever. But, in 
reality, all mankind^ are led by their constitution 
to conclude hardness from this feeling. 

The sensation of heat, and the sensation we have 
by pressing a hard body, are equally feelings ; nor 
can we, by reasoning, draw any conclusion from the 
one but what may be drawn from the other : but, 
by our constitution, we conclude from the first an 
obscure or occult quality, of which we have only 
this relative conception, that it is something 
adapted to raise in us the sensation of heat ; from 
the second, we conclude a quality of which we have 
a clear and distinct conception — to wit, the hardness 
of the body.^ 

§ 4. Of the Visible Appearances of Objects 

In this section we must speak of things which are 
never made the object of reflection, though almost 
every moment presented to the mind. Nature 
intended them only for signs ; and in the whole 
course of hfe they are put to no other use. The 
mind has acquired a confirmed and inveterate habit 
of inattention to them ; for they no sooner appear, 

^ Ibid., pp. 123-125. 

REID 85 

than quick as lightning the thing signified succeeds, 
and engrosses all our regard. They have no name 
in language ; and, although we are conscious of them 
when they pass through the mind, yet their passage 
is so quick and so famiHar, that it is absolutely 
unheeded ; nor do they leave any footsteps of 
themselves, either in the memory or imagination. 
That this is the case with regard to the sensations of 
touch, hath been shewn in the last chapter ; and 
it holds no less with regard to the visible appear- 
ances of objects.^ 

By colour, all men, who have not been tutored 
by modern philosophy, understand, not a sensation 
of the mind, which can have no existence when it 
is not perceived, but a quality or modification of 
bodies, which continues to be the same whether it is 
seen or not. The scarlet-rose which is before me, 
is still a scarlet-rose when I shut my eyes, and was 
so at midnight when no eye saw it. The colour 
remains when the appearance ceases ; it remains 
the same when the appearance changes. For when 
I view this scarlet-rose through a pair of green 
spectacles, the appearance is changed ; but I do not 
conceive the colour of the rose changed. To a 
person in the jaundice, it has still another appear- 
ance; but he is easily convinced that the change 
is in his eye, and not in the colour of the object. 
Every different degree of light makes it have a 

1 Ibid., p. 135. 


different appearance, and total darkness takes 
away all appearance, but makes not the least 
change in the colour of the body. We may, by a 
variety of optical experiments, change the appear- 
ance of figure and magnitude in a body, as well as 
that of colour ; we may make one body appear to 
be ten. But all men beheve, that, as a multiplying 
glass does not really produce ten guineas out of one, 
nor a microscope turn a guinea into a ten-pound 
piece, so neither does a coloured glass change the 
real colour of the object seen through it, when it 
changes the appearance of that colour. 

The common language of mankind shews evi- 
dently, that we ought to distinguish between the 
colour of a body, which is conceived to be a fixed 
and permanent quality in the body, and the appear- 
ance of that colour to the eye, which may be varied 
a thousand ways, by a variation of the light, of 
the medium, or of the eye itself. The permanent 
colour of the body is the cause which, by the 
mediation of various kinds or degrees of light, 
and of various transparent bodies interposed, 
produces all this variety of appearances. When a 
coloured body is presented, there is a certain 
apparition to the eye, or to the mind, which we 
have called the appearance of colour. Mr Locke 
calls it an idea ; and, indeed, it may be called so 
with the greatest propriety. This idea can have 
no existence but when it is perceived. It is a kind 

REID 87 

of thought, and can only be the act of a percipient 
or thinking being. By the constitution of our 
nature, we were led to conceive this idea as a sign of 
something external, and are impatient till we learn 
its meaning. A thousand experiments for this 
purpose are made every day by children, even 
before they come to the use of reason. They look 
at things, they handle them, they put them in 
various positions, at different distances, and in 
different lights. The ideas of sight, by these means, 
come to be associated with, and readily to suggest, 
things external, and altogether unlike them. In 
particular, that idea which we have called the appear- 
ance of colour, suggests the conception and belief 
of some unknown quality in the body which 
occasions the idea ; and it is to this quality, 
and not to the idea, that we give the name of 

Although there is no resemblance, nor, as far as 
we know, any necessary connection between that 
quality in a body which we call its colour, and the 
appearance which that colour makes to the eye, it 
is quite otherwise with regard to its figure and 
magnitude. There is certainly a resemblance, and a 
necessary connection, between the visible figure 
and magnitude of a body, and its real figure and 
magnitude ; no man can give a reason why a 
scarlet colour affects the eye in the manner it does ; 

^ Ihid., pp. 137-138. 


no man can be sure that it affects his eye in the same 
manner as it affects the eye of another, and that it 
has the same appearance to him as it has to another 
man ; — but we can assign a reason why a circle 
placed obliquely to the eye, should appear in the 
form of an ellipse. The visible figure, magnitude, 
and position may, by mathematical reasoning, be 
deduced from the real ; and it may be demon- 
strated, that every eye that sees distinctly and 
perfectly, must, in the same situation, see it under 
this form, and no other. Nay, we may venture 
to afhrm, that a man born blind, if he were in- 
structed in mathematics, would be able to determine 
the visible figure of a body, when its real figure, 
distance, and position, are given. ^ 

Since the visible figure of bodies is a real and 
external object to the eye, as their tangible figure 
is to the touch, it may be asked. Whence arises 
the difficulty of attending to the first, and the 
facility of attending to the last ? It is certain that 
the first is more frequently presented to the eye, 
than the last is to the touch ; the first is as distinct 
and determinate an object as the last, and seems 
in its own nature as proper for speculation. Yet so 
little hath it been attended to, that it never had a 
name in any language, until Bishop Berkeley gave it 
that which we have used after his example, to distin- 
guish it from the figure which is the object of touch. 

^ Ibid., pp. 142-143. 

REID 89 

The difficulty of attending to the visible figure of 
bodies, and making it an object of thought, appears 
so similar to that which we find in attending to our 
sensations, that both have probably like causes. 
Nature intended the visible figure as a sign of the 
tangible figure and situation of bodies, and hath 
taught us, by a kind of instinct, to put it always 
to this use. Hence it happens, that the mind passes 
over it with a rapid motion, to attend to the things 
signified by it. It is as unnatural to the mind 
to stop at the visible figure, and attend to it, as it 
is to a spherical body to stop upon an inclined 
plane. There is an inward principle, which con- 
stantly carries it forward, and which cannot be 
overcome but by a contrary force. ^ 

§ 5. Of Perception in General 

Sensation, and the perception of external objects 
by the senses, though very different in their nature, 
have commonly been considered as one and the 
same thing. The purposes of common life do not 
make it necessary to distinguish them, and the 
received opinions of philosophers tend rather to 
confound them ; but, without attending carefully 
to this distinction, it is impossible to have any just 
conception of the operations of our senses. The 
most simple operations of the mind, admit not of 
a logical definition : all we can do is to describe 

^ Ihid., p. 146. 


them, so as to lead those who are conscious of them 
in themselves, to attend to them, and reflect upon 
them ; and it is often very difficult to describe 
them so as to answer this intention. 

The same mode of expression is used to denote 
sensation and perception ; and, therefore, we are 
apt to look upon them as things of the same nature. 
Thus, I feel a pain ; I see a tree : the first denoteth 
a sensation, the last a perception. The gram- 
matical analysis of both expressions is the same : 
for both consist of an active verb and an object. 
But, if we attend to the things signified by these 
expressions, we shall find that, in the first, the 
distinction between the act and the object is not 
real but grammatical ; in the second, the distinc- 
tion is not only grammatical but real. 

The form of the expression, / feel pain, might 
seem to imply that the feeling is something distinct 
from the pain felt ; yet, in reality, there is no 
distinction. As thinking a thought is an expression 
which could signify no more than thinking, so 
feeling a fain signifies no more than being pained. 
What we have said of pain is applicable to every 
other mere sensation. It is difficult to give in- 
stances, very few of our sensations having names ; 
and, where they have, the name being common 
to the sensation, and to something else which is 
associated with it. But, when we attend to the 
sensation by itself, and separate it from other 

REID 91 

things which are conjoined with it in the imagina- 
tion, it appears to be something which can have no 
existence but in a sentient mind, no distinction from 
the act of the mind by which it is felt. 

Perception, as we here understand it, hath always 
an object distinct from the act by which it is 
perceived; an object which may exist whether it 
be perceived or not. I perceive a tree that grows 
before my window ; there is here an object which is 
perceived, and an act of the mind by which it is 
perceived ; and these two are not only distinguish- 
able, but they are extremely unlike in their natures. 
The object is made up of a trunk, branches, and 
leaves ; but the act of the mind by which it is 
perceived hath neither trunk, branches, nor leaves. 
I am conscious of this act of my mind, and I can 
reflect upon it ; but it is too simple to admit of an 
analysis, and I cannot find proper words to describe 
it. I find nothing that resembles it so much as 
the remembrance of the tree, or the imagination of 
it. Yet both these differ essentially from percep- 
tion ; they differ likewise one from another. It is 
in vain that a philosopher assures me, that the 
imagination of the tree, the remembrance of it, 
and the perception of it, are all one, and differ only 
in degree of vivacity. I know the contrary ; for 
I am as well acquainted with all the three as I am 
with the apartments of my own house. I know 
this also, that the perception of an object implies 


both a conception of its form, and a belief of its 
present existence. I know, moreover, that this 
behef is not the effect of argumentation and reason- 
ing ; it is the immediate effect of my constitution. 

I am aware that this belief which I have in 
perception stands exposed to the strongest batteries 
of scepticism. But they make no great impression 
upon it. The sceptic asks me. Why do you believe 
the existence of the external object which you 
perceive ? This belief, sir, is none of my manu- 
facture ; it came from the mint of Nature ; it bears 
her image and superscription ; and, if it is not right, 
the fault is not mine : I even took it upon trust, 
and without suspicion. Reason, says the sceptic, 
is the only judge of truth, and you ought to throw 
off every opinion and every belief that is not 
grounded on reason. Why, sir, should I believe 
the faculty of reason more than that of perception ? 
— they came both out of the same shop, and were 
made by the same artist ; and if he puts one piece 
of false ware into my hands, what should hinder 
him from putting another ?^ 

Our perceptions are of two kinds : some are 
natural and original ; others acquired, and the 
fruit of experience. When I perceive that this is 
the taste of cyder, that of brandy ; that this is the 
smell of an apple, that of an orange ; that this is 
the noise of thunder, that the ringing of bells ; this 
1 Ibid., pp. 182-183. 

REID 93 

the sound of a coach passing, that the voice of such 
a friend : these perceptions, and others of the same 
kind, are not original — they are acquired. But 
the perception which I have, by touch, of the hard- 
ness and softness of bodies, of their extension, 
figure, and motion, is not acquired — it is original. 

In all our senses, the acquired perceptions are 
many more than the original, especially in sight. 
By this sense we perceive originally the visible 
figure and colour of bodies only, and their visible 
place : but we learn to perceive by the eye almost 
everything which we can perceive by touch. The 
original perceptions of this sense serve only as signs 
to introduce the acquired. 

The signs by which objects are presented to us 
in perception, are the language of Nature to man ; 
and as, in many respects, it hath great affinity with 
the language of man to man, so particularly in this, 
that both are partly natural and original, partly 
acquired by custom. Our original or natural 
perceptions are analogous to the natural language 
of man to man, of which we took notice in the 
fourth chapter ; and our acquired perceptions are 
analogous to artificial language, which, in our 
mother-tongue, is got very much in the same 
manner with our acquired perceptions — as we shall 
afterwards more fully explain. 

Not only men, but children, idiots, and brutes, 
acquire by habit many perceptions which they had 


not originally. Almost every employment in life 
hath perceptions of this kind that are peculiar to it. 
The shepherd knows every sheep of his flock, as 
we do our acquaintance, and can pick them out of 
another flock one by one. The butcher knows by 
sight the weight and quality of his beeves and sheep 
before they are killed. The farmer perceives by 
his eye, very nearly, the quantity of hay in a rick, 
or of corn in a heap. The sailor sees the burthen, 
the build, and the distance of a ship at sea, while 
she is a great way off. Every man accustomed to 
writing, distinguishes his acquaintance by their 
handwriting, as he does by their faces. And the 
painter distinguishes, in the works of his art, the 
style of all the great masters. In a word, acquired 
perception is very different in different persons, 
according to the diversity of objects about which 
they are employed, and the application they 
bestow in observing them. 

Perception ought not only to be distinguished 
from sensation, but likewise from that knowledge 
of the objects of sense which is got by reasoning. 
There is no reasoning in perception, as hath been 
observed. The belief which is implied in it, is the 
eflect of instinct. But there are many things, with 
regard to sensible objects, which we can infer from 
what we perceive ; and such conclusions of reason 
ought to be distinguished from what is merely 
perceived. When I look at the moon, I perceive 

REID 95 

her to be sometimes circular, sometimes horned, 
and sometimes gibbous. This is simple perception, 
and is the same in the philosopher and in the clown : 
but from these various appearances of her enlight- 
ened part, I infer that she is really of a spherical 
figure. This conclusion is not obtained by simple 
perception, but by reasoning. Simple perception 
has the same relation to the conclusions of reason 
drawn from our perceptions, as the axioms in 
mathematics have to the propositions. I cannot 
demonstrate that two quantities which are equal 
to the same quantity, are equal to each other ; 
neither can I demonstrate that the tree which I 
perceive, exists. But, by the constitution of my 
nature, my belief is irresistibly carried along by my 
apprehension of the axiom ; and, by the constitu- 
tion of my nature, my belief is no less irresistibly 
carried along by my perception of the tree. All 
reasoning is from principles. The first principles 
of mathematical reasoning are mathematical 
axioms and definitions ; and the first principles 
of all our reasoning about existences, are our 
perceptions. The first principles of every kind of 
reasoning are given us by Nature, and are of equal 
authority with the faculty of reason itself, which 
is also the gift of Nature. The conclusions of 
reason are all built upon first principles, and can 
have no other foundation. Most justly, therefore, 
do such principles disdain to be tried by reason, and 


laugh at all the artillery of the logician, when it is 
directed against them. 

When a long train of reasoning is necessary in 
demonstrating a mathematical proposition, it is 
easily distinguished from an axiom ; and they seem 
to be things of a very different nature. But there 
are some propositions which lie so near to axioms 
that it is difficult to say whether they ought to be 
held as axioms, or demonstrated as propositions. 
The same thing holds with regard to perception, and 
the conclusions drawn from it. Some of these 
conclusions follow our perceptions so easily, and are 
so immediately connected with them, that it is 
difficult to fix the limit which divides the one from 
the other. 

Perception, whether original or acquired, implies 
no exercise of reason ; and is common to men, 
children, idiots, and brutes. The more obvious 
conclusions drawn from our perceptions, by reason, 
make what we call common understanding ; by 
which men conduct themselves in the common 
affairs of life, and by which they are distinguished 
from idiots. The more remote conclusions which 
are drawn from our perceptions, by reason, make 
what we commonly call science in the various parts 
of nature, whether in agriculture, medicine, 
mechanics, or in any part of natural philosophy. 
When I see a garden in good order, containing a 
great variety of things of the best kinds, and in 

REID 97 

the most flourishing condition, I immediately 
conclude from these signs the skill and industry 
of the gardener. A farmer, when he rises in the 
morning, and perceives that the neighbouring 
brook overflows his field, concludes that a great 
deal of rain hath fallen in the night. Perceiving 
his fence broken, and his corn trodden down, he 
concludes that some of his own or his neighbours' 
cattle have broke loose. Perceiving that his 
stable door is broke open, and some of his horses 
gone, he concludes that a thief has carried them off. 
He traces the prints of his horses' feet in the soft 
ground, and by them discovers which road the thief 
hath taken. These are instances of common 
understanding, which dwells so near to perception 
that it is difficult to trace the line which divides the 
one from the other. In like manner, the science 
of nature dwells so near to common understanding 
that we cannot discern where the latter ends and 
the former begins. I perceive that bodies lighter 
than water swim in water, and that those which are 
heavier sink. Hence I conclude, that, if a body 
remains wherever it is put under water, whether at 
the top or bottom, it is precisely of the same weight 
with water. If it will rest only when part of it is 
above water, it is lighter than water. And the 
greater the part above water is, compared with the 
whole, the lighter is the body. If it had no gravity 
at all, it would make no impression upon the water, 



but stand wholly above it. Thus, every man, by 
common understanding, has a rule by which he 
judges of the specific gravity of bodies which swim 
in water : and a step or two more leads him into 
the science of hydrostatics. 

All that we know of nature, or of existences, may 
be compared to a tree, which hath its root, trunk, 
and branches. In this tree of knowledge, per- 
ception is the root, common understanding is the 
trunk, and the sciences are the branches. 

§ 6. Of the Process of Nature in Perception 

Although there is no reasoning in perception, 
yet there are certain means and instruments, 
which, by the appointment of nature, must inter- 
vene between the object and our perception of it ; 
and, by these, our perceptions are limited and 
regulated. First, If the object is not in contact 
with the organ of sense, there must be some medium 
which passes between them. Thus, in vision, the 
rays of light ; in hearing, the vibrations of elastic 
air ; in smelling, the effluvia of the body smelled — 
must pass from the object to the organ ; otherwise 
we have no perception. Secondly, There must be 
some action or impression upon the organ of sense, 
either by the immediate application of the object, 
or by the medium that goes between them. 
Thirdly, The nerves which' go from the brain to 
the organ must receive some impression by means 

REID 99 

of that which was made upon the organ ; and, 
probably, by means of the nerves, some impression 
must be made upon the brain. Fourthly, The 
impression made upon the organ, nerves, and brain, 
is followed by a sensation. And, last of all. This 
sensation is followed by the perception of the object. 

Thus, our perception of objects is the result of a 
train of operations ; some of which affect the body 
only, others affect the mind. We know very little 
of the nature of some of these operations ; we know 
not at all how they are connected together, or in 
what way they contribute to that perception which 
is the result of the whole ; but, by the laws of our 
constitution, we perceive objects in this, and in no 
other way.^ 

Experience teaches us, that certain impressions 
upon the body are constantly followed by certain 
sensations of the mind ; and that, on the other 
hand, certain determinations of the mind are 
constantly followed by certain motions of the body ; 
but we see not the chain that ties these things 
together. Who knows but their connection may 
be arbitrary, and owing to the will of our Maker ? 
Perhaps the same sensations might have been con- 
nected with other impressions, or other bodily 
organs. Perhaps we might have been so made as 
to taste with our fingers, to smell with our ears, 
and to hear by the nose. Perhaps we might have 

1 Ihid., pp. 184-186. 


been so made as to have all the sensations and 
perceptions which we have, without any impression 
made upon our bodily organs at all. 

However these things may be, if Nature had given 
us nothing more than impressions made upon the 
body, and sensations in our minds corresponding 
to them, we should, in that case, have been merely 
sentient, but not percipient beings. We should 
never have been able to form a conception of any 
external object, far less a belief of its existence. 
Our sensations have no resemblance to external 
objects ; nor can we discover, by our reason, any 
necessary connection between the existence of 
the former, and that of the latter.^ 

Appendix: Of Cause and Power 

It is proper here to explain what is meant by 
the cause of a phenomenon, when that word is used 
in natural philosophy. The word cause is so am- 
biguous, that I fear many mistake its meaning, 
and take it to mean the efficient cause, which I 
think it never does in this science. 

By the cause of a phenomenon, nothing is meant 
but the law of nature, of which that phenomenon 
is an instance, or a necessary consequence. The 
cause of a body's faUing to the ground is its gravity. 
But gravity is not an efficient cause, but a general 
law, that obtains in nature, of which law the fall 

* Ibid., p. 187. 

RE ID loi 

of this body is a particular instance. The cause 
why a body projected moves in a parabola, is, that 
this motion is the necessary consequence of the pro- 
jectile force and gravity united. But these are 
not efficient causes ; they are only laws of nature. 
In natural philosophy, therefore, we seek only the 
general laws, according to which nature works, 
and these we call the causes of what is done accord- 
ing to them. But such laws cannot be the efficient 
cause of anything. They are only the rule accord- 
ing to which the efficient cause operates. 

A natural philosopher may search after the cause 
of a law of nature ; but this means no more than 
searching for a more general law, which includes 
that particular law, and perhaps many others under 
it. This was all that Newton aimed at by his 
ether. He thought it possible, that, if there was 
such an ether, the gravitation of bodies, the re- 
flection and refraction of the rays of light, and many 
other laws of nature, might be the necessary con- 
sequences of the elasticity and repelling force of 
the ether. But, supposing this ether to exist, its 
elasticity and repelling force must be considered 
as a law of nature ; and the efficient cause of this 
elasticity would still have been latent. 

Efficient causes, properly so called, are not 
\vithin the sphere of natural philosophy. Its 
business is, from particular facts in the material 
world, to collect, by just induction, the laws that 


are general, and from these the more general, as 
far as we can go. And when this is done, natural 
philosophy has no more to do. It exhibits to our 
view the grand machine of the material world, 
analysed, as it were, and taken to pieces, with the 
connections and dependencies of its several parts, 
and the laws of its several movements. It belongs 
to another branch of philosophy to consider whether 
this machine is the work of chance or of design, 
and whether of good or of bad design ; whether 
there is not an intelligent first Mover who con- 
trived the whole, and gives motion to the whole, 
according to the laws which the natural philosopher 
has discovered, or, perhaps, according to laws 
still more general, of which we can only discover 
some branches ; and whether he does these things 
by his own hand, so to speak, or employs sub- 
ordinate efficient causes to execute his purposes. 
These are very noble and important inquiries, but 
they do not belong to natural philosophy ; nor 
can we proceed in them in the way of experiment 
and induction, the only instruments the natural 
philosopher uses in his researches. 

Whether you call this branch of philosophy 
Natural Theology or Metaphysics, I care not ; but 
I think it ought not to be confounded with Natural 
Philosophy ; and neither of them with Mathe- 
matics. Let the mathematician demonstrate the 
relation of abstract quantity ; the natural philo- 

REID 103 

sopher investigate the laws of the material system 
by induction ; and the metaphysician, the final 
causes, and the efficient causes of what we see and 
what natural philosophy discovers in the world we 
live in. 

As to final causes, they stare us in the face 
wherever we cast our eyes. I can no more doubt 
whether the eye was made for the purpose of seeing, 
and the ear of hearing, than I can doubt of a mathe- 
matical axiom ; yet the evidence is neither mathe- 
matical demonstration, nor is it induction. In a 
word, final causes, good final causes, are seen 
plainly everywhere : in the heavens and in the earth ; 
in the constitution of every animal, and in our own 
constitution of body and of mind ; and they are 
most worthy of observation, and have a charm 
in them that delights the soul. 

As to efficient causes, I am afraid our faculties 
carry us but a very little way, and almost only to 
general conclusions. I hold it to be self-evident, 
that every production, and every change in nature, 
must have an efficient cause that has power to 
produce the effect ; and that an effect which has 
the most manifest marks of intelligence, wisdom, 
and goodness, must have an intelligent, wise, and 
good efficient cause. From these, and some such 
self-evident truths, we may discover the principles 
of natural theology, and that the Deity is the first 
efficient cause of all nature. But how far he 


operates in nature immediately, or how far by the 
ministry of subordinate efficient causes, to which he 
has given power adequate to the task committed 
to them, I am afraid our reason is not able to dis- 
cover, and we can do little else than conjecture. 
We are led by nature to believe ourselves to be the 
efficient causes of our own voluntary actions ; and, 
from analogy, we judge the same of other intelhgent 
beings. But with regard to the works of nature, 
I cannot recollect a single instance wherein I can 
say, with any degree of assurance, that such a 
thing is the efficient cause of such a phenomenon 
of nature. 

I never could see good reason to believe that 
matter has any active power at all. And, indeed, 
if it were evident that it has one, I think there could 
be no good reason assigned for not allowing it 
others. Your Lordship speaks of the power of 
resisting motion, and some others, as acknowledged 
active powers inherent in matter. As to the re- 
sistance to motion, and the continuance in motion, 
I never could satisfy myself whether these are not 
the necessary consequences of matter being inactive. 
If they imply activity, they may lie in some other 

I am not able to form any distinct conception 
of active power but such as I find in myself. I can 
only exert my active power by will, which supposes 
thought. It seems to me, that, if I was not con- 

REID 105 

scious of activity in myself, I could never, from 
things I see about me, have had the conception 
or idea of active power. I see a succession of 
changes, but I see not the power, that is, the 
efficient cause of them ; but, having got the notion 
of active power, from the consciousness of my 
own activity, and finding it a first principle, that 
every production requires active power, I can 
reason about an active power of that kind I am 
acquainted with — that is, such as supposes thought 
and choice, and is exerted by will. But, if there 
is anything in an unthinking inanimate being that 
can be called active power, I know not what it is, 
and cannot reason about it. 

If you conceive that the activity of matter is 
directed by thought and will in matter, every 
particle of matter must know the situation and dis- 
tance of every other particle within the planetary 
system ; but this, I am apt to think, is not your 
Lordship's opinion. 

I must therefore conclude, that this active power 
is guided in all its operations by some intelligent 
Being, who knows both the law of gravitation, and 
the distance and situation of every particle of matter 
with regard to every other particle, in all the 
changes that happen in the material world. I can 
only conceive two ways in which this particle of 
matter can be guided, in all the exertions of its 
active power, by an intelligent Being. Either it 


was formed, in its creation, upon a foreknowledge 
of all the situations it shall ever be in with respect 
to other particles, and had such an internal struc- 
ture given it, as necessarily produces, in succession, 
all the motions, and tendencies to motion, it shall 
ever exert. This would make every particle of 
matter a machine or automaton, and every particle 
of a different structure from every other particle 
in the universe. This is indeed the opinion of Leib- 
nitz ; but I am not prejudiced against it upon that 
account ; I only wished to know whether your 
Lordship adopted it or not. Another way, and the 
only other way, in which I can conceive the active 
power of a particle of matter, guided by an intelli- 
gent Being, is by a continual influence exerted 
according to its situation and the situation of other 
particles. In this case, the particle would be 
guided as a horse is by his rider ; and I think it 
would be improper to ascribe to it the power of 
gravitation. It has only the power of obeying its 
guide. Whether your Lordship chooses the first 
or the last in this alternative, I should be glad to 
know ; or whether you can think of a third way 
better than either. ^ 

The ambiguity of the words power, cause, agent, 
and of all the words related to these, tends to 
perplex this question. The weakness of human 

1 " Letter to Lord Kames," i6th Dec. 1780 {Works, vol. i. 
pp. 56-59). 

REID 107 

understanding, which gives us only an indirect and 
relative conception of power, contributes to darken 
our reasoning, and should make us cautious and 
modest in our determinations. 

We can derive little light in this matter from the 
events which we observe in the course of nature. 
We perceive changes innumerable in things without 
us. We know that those changes must be pro- 
duced by the active power of some agent ; but we 
neither perceive the agent nor the power, but the 
change only. Whether the things be active, or 
merely passive, is not easily discovered. And 
though it may be an object of curiosity to the 
speculative few, it does not greatly concern the 

From the course of events in the natural world, 
we have sufficient reason to conclude the existence 
of an eternal intelligent First Cause. But whether 
He acts immediately in the production of those 
events, or by subordinate intelligent agents, or by 
instruments that are unintelligent, and what the 
number, the nature, and the different offices, of 
those agents or instruments may be — these I 
apprehend to be mysteries placed beyond the limits 
of human knowledge. We see an established order 
in the succession of natural events, but we see not 
the bond that connects them together. 

Since we derive so little light, with regard to 
efficient causes and their active power, from atten- 


tion to the natural world, let us next attend to the 
moral, I mean to human actions and conduct. 

When I observe a plant growing from its seed to 
maturity, I know that there must be a cause that 
has power to produce this effect. But I see neither 
the cause nor the manner of its operation. 

But, in certain motions of my body and directions 
of my thought, I know not only that there must be a 
cause that has power to produce these effects, but 
that I am that cause ; and I am conscious of what 
I do in order to the production of them. 

From the consciousness of our own activity, 
seems to be derived not only the clearest, but the 
only conception we can form of activity, or the 
exertion of active power. 

As I am unable to form a notion of any intellect- 
ual power different in kind from those I possess, the 
same holds with respect to active power. If all 
men had been blind, we should have had no con- 
ception of the power of seeing, nor any name for it 
in language. If man had not the powers of ab- 
straction and reasoning, we could not have had any 
conception of these operations. In like manner, 
if he had not some degree of active power, and if 
he were not conscious of the exertion of it in his 
voluntary actions, it is probable he could have no 
conception of activity, or of active power. 

A train of events following one another ever so 
regularly, could never lead us to the notion of a 

REID 109 

cause, if we had not, from our constitution, a con- 
viction of the necessity of a cause to every event. 

And of the manner in which a cause may exert 
its active power, we can have no conception, but 
from consciousness of the manner in which our 
active power is exerted. 

Every man is led by nature to attribute to 
himself the free determinations of his own will, and 
to believe those events to be in his power which 
depend upon his will. On the other hand, it is 
self-evident, that nothing is in our power that is not 
subject' to our will. 

We grow from childhood to manhood, we digest 
our food, our blood circulates, our heart and 
arteries beat, we are sometimes sick and sometimes 
in health ; all these things must be done by the 
power of some agent ; but they are not done by 
our power. How do we know this ? Because they 
are not subject to our will. This is the infallible 
criterion by which we distinguish what is our doing 
from what is not ; what is in our power from what 
is not. 

Human power, therefore, can only be exerted by 
will, and we are unable to conceive any active power 
to be exerted without will. Every man knows 
infallibly that what is done by his conscious will 
and intention, is to be imputed to him, as the agent 
or cause ; and that whatever is done without his will 
and intention, cannot be imputed to him with truth. 


We judge of the actions and conduct of other men 
by the same rule as we judge of our own. In 
morals, it is self-evident that no man can be the 
object either of approbation or of blame for what 
he did not. But how shall we know whether 
it is his doing or not ? If the action depended 
upon his will, and if he intended and willed it, it is 
his action in the judgment of all mankind. But 
if it was done without his knowledge, or without 
his will and intention, it is as certain that he did it 
not, and that it ought not to be imputed to him as 
the agent. 

Now it is evident that, to constitute the relation 
between me and my action, my conception of the 
action, and will to do it, are essential. For what I 
never conceived nor willed, I never did. 

If any man, therefore, affirms, that a being may 
be the efficient cause of an action, and have power 
to produce it, which that being can neither conceive 
nor will, he speaks a language which I do not 
understand. If he has a meaning, his notion of 
power and efficiency must be essentially different 
from mine ; and, until he conveys his notion of 
efficiency to my understanding, I can no more 
assent to his opinion than if he should affirm that 
a being without life may feel pain. 

It seems, therefore, to me most probable, that 
such beings only as have some degree of under- 
standing and will, can possess active power ; and 


that inanimate beings must be merely passive, and 
have no real activity. Nothing we perceive with- 
out us affords any good ground for ascribing active 
power to any inanimate being ; and everything we 
can discover in our own constitution, leads us to 
think that active power cannot be exerted without 
will and intelligence. ^ 


§ I. Principles taken for Granted 

As there are words common to philosophers and 
to the vulgar, which need no explication, so there 
are principles common to both, which need no 
proof, and which do not admit of direct pxoof.^ 

I. First, then, I shall take it for granted, that 
I think, that I rememher, that I reason, and, in 
general, that I really perform all those operations 
of mind of which I am conscious. 

The operations of our minds are attended with 
consciousness ; and this consciousness is the evi- 
dence, the only evidence, which we have or can 
have of their existence. If a man should take it 
into his head to think or to say that his consciousness 
may deceive him, and to require proof that it cannot, 
I know of no proof that can be given him ; he must 

1 " Essays on the Active Powers of Man " {Works, vol. ii. 
pp. 522-525). 

2 " Essays on the Intellectual Powers of Man " {Works, vol. i. 
p. 230). 


be left to himself, as a man that denies first prin- 
ciples, without which there can be no reasoning. 
Every man finds himself under a necessity of believ- 
ing what consciousness testifies, and everything that 
hath this testimony is to be taken as a first principle. 

2. As by consciousness we know certainly the 
existence of our present thoughts and passions ; 
so we know the past by remembrance. And, when 
they are recent, and the remembrance of them 
fresh, the knowledge of them, from such distinct 
remembrance, is, in its certainty and evidence, 
next to that of consciousness. 

3. But it is to be observed that we are conscious 
of many things to which we give little or no 
attention. .We can hardly attend to several things 
at the same time ; and our attention is commonly 
employed about that which is the object of our 
thought, and rarely about the thought itself. Thus, 
when a man is angry, his attention is turned to the 
injury done him, or the injurious person ; and he 
gives very little attention to the passion of anger, 
although he is conscious of it. It is in our power, 
however, when we come to the years of under- 
standing, to give attention to our own thoughts and 
passions, and the various operations of our minds. 
And, when we make these the objects of our atten- 
tion, either while they are present or when they 
are recent and fresh in our memory, this act of the 
mind is called reflection. 

REID 113 

We take it for granted, therefore, that, by atten- 
tive reflection, a man may have a clear and certain 
knowledge of the operations of his own mind ; a 
knowledge no less clear and certain than that which 
he has of an external object when it is set before 
his eyes. 

This reflection is a kind of intuition, it gives a 
like conviction with regard to internal objects, or 
things in the mind, as the faculty of seeing gives 
with regard to objects of sight. A man must, 
therefore, be convinced beyond possibility of doubt, 
of everything with regard to the operations of his 
own mind, which he clearly and distinctly discerns 
by attentive reflection. 

4. I take it for granted that all the thoughts I am 
conscious of, or remember, are the thoughts of one 
and the same thinking principle, which I call 
myself, or my mind. Every man has an immediate 
and irresistible conviction, not only of his present 
existence, but of his continued existence and 
identity, as far back as he can remember. If any 
man should think fit to demand a proof that the 
thoughts he is successively conscious of, belong to 
one and the same thinking principle — if he should 
demand a proof that he is the same person to-day 
as he was yesterday, or a year ago — I know no proof 
that can be given him : he must be left to himself, 
either as a man that is lunatic, or as one who denies 
first principles, and is not to be reasoned with. 



Every man of a sound mind, finds himself under 
a necessity of believing his own identity, and con- 
tinued existence. The conviction of this is imme- 
diate and irresistible ; and, if he should lose this 
conviction, it would be a certain proof of insanity, 
which is not to be remedied by reasoning. 

5. I take it for granted, that there are some 
things which cannot exist by themselves, but must 
be in something else to which they belong, as 
qualities, or attributes. 

Thus, motion cannot exist, but in something 
that is moved. And to suppose that there can be 
motion while everything is at rest, is a gross and 
palpable absurdity. In Hke manner, hardness and 
softness, sweetness and bitterness, are things 
which cannot exist by themselves ; they are qual- 
ities of something which is hard or soft, sweet or 
bitter. That thing, whatever it be, of which they 
eire qualities, is called their subject ; and such 
qualities necessarily suppose a subject. 

Things which may exist by themselves, and do 
not necessarily suppose the existence of anything 
else, are called substances ; and, with relation to 
the qualities or attributes that belong to them, 
they are called the subjects of such quahties or 

All the things which we immediately perceive 
by our senses, and all the things we are conscious 
of, are things which must be in something else, as 

REID 115 

their subject. Thus, by my senses, I perceive 
figure, colour, hardness, softness, motion, resistance, 
and such like things. But these are qualities, and 
must necessarily be in something that is figured, 
coloured, hard or soft, that moves, or resists. It 
is not to these qualities, but to that which is the 
subject of them, that we give the name of body. 
If any man should think fit to deny that these 
things are qualities, or that they require any 
subject, I leave him to enjoy his opinion as a man 
who denies first principles, and is not fit to be 
reasoned with. If he has common understanding, 
he will find that he cannot converse half an hour 
without saying things which imply the contrary of 
what he professes to believe. 

In like manner, the things I am conscious of, such 
as thought, reasoning, desire, necessarily suppose 
something that thinks, that reasons, that desires. 
We do not give the name of mind to thought, 
reason, or desire ; but to that being which thinks, 
which reasons, and which desires. 

That every act or operation, therefore, supposes 
an agent, that every quahty supposes a subject, 
are things which I do not attempt to prove, but 
take for granted.^ 

6. I take it for granted, that, in most operations 
of the mind, there must be an object distinct from 
the operation itself. I cannot see, without seeing 
^ Ibid., p. 232. 


something. To see without having any object of 
sight is absurd. I cannot remember, without 
remembering something. The thing remembered 
is past, while the remembrance of it is present ; 
and, therefore, the operation and the object of it 
must be distinct things* 

7. We ought Hkewise to take for granted, as first 
principles, things wherein we find an universal 
agreement, among the learned and unlearned, in the 
different nations and ages of the world. 

8. I need hardly say that I shall also take for 
granted such facts as are attested to the conviction 
of all sober and reasonable men, either by our senses, 
by memory, or by human testimony.^ 

Upon the whole, I acknowledge that we ought 
to be cautious that we do not adopt opinions as 
first principles which are not entitled to that 
character. But there is surely the least danger 
of men's being imposed upon in this way, when such 
principles openly lay claim to the character, and 
are thereby fairly exposed to the examination 
of those who may dispute their authority. We do 
not pretend that those things that are laid down 
as first principles may not be examined, and that 
we ought not to have our ears open to what may be 
pleaded against their being admitted as such. 
Let us deal with them as an upright judge does 
with a witness who has a fair character. He pays 

1 Ibid., p. 233. 

REID 117 

a regard to the testimony of such a witness while 
his character is unimpeached ; but, if it can be 
shown that he is suborned, or that he is influenced 
by malice or partial favour, his testimony loses all 
its credit, and is justly rejected.^ 

§ 2. Of Hypotheses and Analogy 

Let us lay down this as a fundamental principle 
in our inquiries into the structure of the mind and 
its operation — that no regard is due to the con- 
jectures or hypotheses of philosophers, however 
ancient, however generally received. Let us accus- 
tom ourselves to try every opinion by the touch- 
stone of fact and experience. What can fairly be 
deduced from facts duly observed or sufficiently 
attested, is genuine and pure ; it is the voice of 
God, and no fiction of human imagination. 

If a philosopher, therefore, pretends to shew us 
the cause of any natural effect, whether relating 
to matter or to mind, let us first consider whether 
there is sufficient evidence that the cause he assigns 
does really exist. If there is not, reject it with 
disdain, as a fiction which ought to have no place 
in genuine philosophy. If the cause assigned 
really exists, consider, in the next place, whether 
the effect it is brought to explain necessarily 
follows from it. Unless it has these two conditions, 
it is good for nothing. ^ 

1 Ibid., p. 234. 2 Ibid., p. 236. 


The conclusion I would draw from all that has 
been said on analogy, is, that, in our inquiries 
concerning the mind and its operations, we ought 
never to trust to reasonings drawn from some 
supposed similitude of body to mind ; and that we 
ought to be very much upon our guard that we be 
not imposed upon by those analogical terms and 
phrases, by which the operations of the mind are 
expressed in all languages.^ 

§ 3. Of Perception 

If we attend to that act of our mind which we 
call the perception of an external object of sense, 
we shall find in it these three things : — First, Some 
conception or notion of the object perceived ; 
Secondly, A strong and irresistible conviction and 
belief of its present existence ; and, Thirdly, That 
this conviction and belief are immediate, and not 
the effect of reasoning. 

First, It is impossible to perceive an object 
without having some notion or conception of that 
which we perceive. We may, indeed, conceive an 
object which we do not perceive ; but, when we 
perceive the object, we must have some perception 
of it at the same time ; and we have commonly a 
more clear and steady notion of the object while we 
perceive it, than we have from memory or imagina- 
tion when it is not perceived. Yet, even in per- 

> Ibid., p. 238. 

REID 119 

ception, the notion which our senses give of the 
object may be more or less clear, more or less 
distinct, in all possible degrees. 

Thus we see more distinctly an object at a small 
than at a great distance. An object at a great dis- 
tance is seen more distinctly in a clear than in a 
foggy day. An object seen indistinctly with the 
naked eye, on account of its smallness, may be seen 
distinctly with a microscope. The objects in this 
room will be seen by a person in the room less and 
less distinctly as the light of the day fails ; they 
pass through all the various degrees of distinct- 
ness according to the degrees of the light, and, 
at last, in total darkness they are not seen at 
all. What has been said of the objects of sight 
is so easily applied to the objects of the other 
senses, that the application may be left to the 

In a matter so obvious to every person capable 
of reflection, it is necessary only farther to observe, 
that the notion which we get of an object, merely 
by our external sense, ought not to be confounded 
with that more scientific notion which a man, come 
to the years of understanding, may have of the 
same object, by attending to its various attributes, 
or to its various parts, and their relation to each 
other, and to the whole. Thus, the notion which a 
child has of a jack for roasting meat, will be acknow- 
ledged to be very different from that of a man who 


understands its construction, and perceives the 
relation of the parts to one another, and to the 
whole. The child sees the jack and every part 
of it as well as the man. The child, therefore, 
has all the notion of it which sight gives ; whatever 
there is more in the notion which the man forms of 
it, must be derived from other powers of the mind, 
which may afterwards be explained. This observa- 
tion is made here only that we may not confound 
the operations of different powers of the mind, 
which by being always conjoined after we grow 
up to understanding, are apt to pass for one and 
the same. 

Secondly, In perception we not only have a 
notion more or less distinct of the object perceived, 
but also an irresistible conviction and belief of its 
existence. This is always the case when we are 
certain that we perceive it. There may be a per- 
ception so faint and indistinct as to leave us in 
doubt whether we perceive the object or not. Thus, 
when a star begins to twinkle as the light of the sun 
withdraws, one may, for a short time, think he 
sees it without being certain, until the perception 
acquire some strength and steadiness. When a 
ship just begins to appear in the utmost verge of the 
horizon, we may at first be dubious whether we 
perceive it or not ; but when the perception is in 
any degree clear and steady, there remains no doubt 
of its reality ; and when the reality of the percep- 

REID 121 

tion is ascertained, the existence of the object 
perceived can no longer be doubted.^ 

I observed, Thirdly, That this conviction is not 
only irresistible, but it is immediate ; that is, it is 
not by a train of reasoning and argumentation that 
we come to be convinced of the existence of what we 
perceive ; we ask no argument for the existence of the 
object, but that we perceive it; perception commands 
our belief upon its own authority, and disdains to 
rest its authority upon any reasoning whatsoever. 

The conviction of a truth may be irresistible, 
and yet not immediate. Thus, my conviction 
that the three angles of every plain triangle are 
equal to two right angles, is irresistible, but it is not 
immediate ; I am convinced of it by demonstrative 
reasoning. There are other truths in mathematics 
of which we have not only an irresistible but an 
immediate conviction. Such are the axioms. Our 
belief of the axioms in mathematics is not grounded 
upon argument — arguments are grounded upon 
them ; but their evidence is discerned immediately 
by the human understanding. 

It is, no doubt, one thing to have an immediate 
conviction of a self-evident axiom ; it is another 
thing to have an immediate conviction of the 
existence of what we see ; but the conviction is 
equally immediate and equally irresistible in both 
cases. 2 

1 Ibid., p. 258. 2 ii,icl., pp. 259-260. 


§ 4. Of Sensation 

Almost all our perceptions have corresponding 
sensations which constantly accompany them, and, 
on that account, are very apt to be confounded with 
them. Neither ought we to expect that the sensa- 
tion, and its corresponding perception, should be 
distinguished in common language, because the 
purposes of common life do not require it. Lan- 
guage is made to serve the purposes of ordinary 
conversation ; and we have no reason to expect 
that it should make distinctions that are not of 
common use. Hence it happens, that a quality 
perceived, and the sensation corresponding to that 
perception, often go under the same name. 

This makes the names of most of our sensations 
ambiguous, and this ambiguity hath very much per- 
plexed philosophers. It will be necessary to give 
some instances, to illustrate the distinction between 
our sensations and the objects of perception. 

When I smell a rose, there is in this operation 
both sensation and perception. The agreeable 
odour I feel, considered by itself, without relation 
to any external object, is merely a sensation. It 
affects the mind in a certain way ; and this affection 
of the mind may be conceived, without a thought 
of the rose, or any other object. This sensation 
can be nothing else than it is felt to be. Its very 
essence consists in being felt ; and, when it is not 

REID 123 

felt, it is not. There is no difference between the 
sensation and the feeling of it — they are one and 
the same thing. It is for this reason that we before 
observed that, in sensation, there is no object dis- 
tinct from that act of the mind by which it is felt — 
and this holds true with regard to all sensations. 

Let us next attend to the perception which we 
have in smelling a rose. Perception has always 
an external object ; and the object of my perception, 
in this case, is that quality in the rose which I 
discern by the sense of smell. Observing that the 
agreeable sensation is raised when the rose is near, 
and ceases when it is removed, I am led, by my 
nature, to conclude some quality to be in the rose, 
which is the cause of this sensation. This quality 
in the rose is the object perceived ; and that act 
of my mind by which I have the conviction and 
belief of this quality, is what in this case I call 

But it is here to be observed, that the sensation 
I feel, and the quality in the rose which I perceive, 
are both called by the same name. The smell of 
a rose is the name given to both : so that this 
name hath two meanings ; and the distinguishing 
its different meaning removes all perplexity, and 
enables us to give clear and distinct answers to 
questions about which philosophers have held much 

Thus, if it is asked, whether the smell be in the 


rose, or in the mind that feels it, the answer is 
obvious : That there are two different things 
signified by the smell of a rose ; one of which is in 
the mind, and can be in nothing but in a sentient 
being ; the other is truly and properly in the rose. 
The sensation which I feel is in my mind. The 
mind is the sentient being ; and, as the rose is 
insentient, there can be no sensation, nor anything 
resembling sensation in it. But this sensation in 
my mind is occasioned by a certain quality in the 
rose, which is called by the same name with the 
sensation, not on account of any similitude, but 
because of their constant concomitancy. 

All the names we have for smells, tastes, sounds, 
and for the various degrees of heat and cold, have a 
like ambiguity ; and what has been said of the smell 
of a rose may be applied to them. They signify 
both a sensation, and a quality perceived by means 
of that sensation. The first is the sign, the last 
the thing signified. As both are conjoined by 
nature, and as the purposes of common life do not 
require them to be disjoined in our thoughts, they 
are both expressed by the same name : and this 
ambiguity is to be found in all languages, because 
the reason of it extends to all.^ 

Sensation, taken by itself, implies neither the 
conception nor belief of any external object. It 
supposes a sentient being, and a certain manner in 
^ Ibid., p. 310. 

REID 125 

which that being is affected ; but it supposes no 
more. Perception implies an immediate conviction 
and belief of something external — something 
different both from the mind that perceives, 
and from the act of perception. Things so 
different in their nature ought to be distinguished ; 
but, by our constitution, they are always united. 
Every different perception is conjoined with a sen- 
sation that is proper to it. The one is the sign, the 
other the thing signified. They coalesce in our 
imagination. They are signified by one name, 
and are considered as one simple operation. The 
purposes of life do not require them to be dis- 

It is the philosopher alone who has occasion to 
distinguish them, when he would analyse the opera- 
tion compounded of them. But he has no suspicion 
that there is any composition in it ; and to discover 
this requires a degree of reflection which has been 
too little practised even by philosophers.^ 

§ 5. Of Primary and Secondary Qualities 

Every one knows that extension, divisibility, 
figure, motion, solidity, hardness, softness, and 
fluidity, were by Mr Locke called primary qualities 
of body ; and that sound, colour, taste, smell, 
and heat or cold, were called secondary qualities. 
Is there a just foundation for this distinction ? 

^ Ibid., p. 312. 


Is there anything common to the primary which 
belongs not to the secondary ? And what is it ? 

I answer, That there appears to me to be a real 
foundation for the distinction ; and it is this — 
that our senses give us a direct and a distinct 
notion of the primary qualities, and inform us what 
they are in themselves. But of the secondary 
qualities, our senses give us only a relative and ob- 
scure notion. They inform us only, that they are 
qualities that affect us in a certain manner — that 
is, produce in us a certain sensation ; but as to 
what they are in themselves, our senses leave us 
in the dark. 

Every man capable of reflection may easily 
satisfy himself that he has a perfectly clear and 
distinct notion of extension, divisibility, figure, and 
motion. The solidity of a body means no more 
but that it excludes other bodies from occupying 
the same place at the same time. Hardness, soft- 
ness, and fluidity are different degrees of cohesion in 
the parts of a body. It is fluid when it has no 
sensible cohesion ; soft, when the cohesion is weak ; 
and hard, when it is strong. Of the cause of this 
cohesion we are ignorant, but the thing itself we 
understand perfectly, being immediately informed 
of it by the sense of touch. It is evident, therefore, 
that of the primary qualities we have a clear and 
distinct notion ; we know what they are, though 
we may be ignorant of their causes. 

REID 127 

I observed, farther, that the notion we have of 
primary quaUties is direct, and not relative only. 
A relative notion of a thing, is, strictly speaking, 
no notion of the thing at all, but only of some 
relation which it bears to something else. 

Thus, gravity sometimes signifies the tendency of 
bodies towards the earth ; sometimes it signifies 
the cause of that tendency. When it means the 
first, I have a direct and distinct notion of gravity ; 
I see it, and feel it, and know perfectly what it is ; 
but this tendency must have a cause. We give 
the same name to the cause ; and that cause has 
been an object of thought and of speculation. Now, 
what notion have we of this cause when we think 
and reason about it ? It is evident we think of it 
as an unknown cause, of a known effect. This is a 
relative notion ; and it must be obscure, because it 
gives us no conception of what the thing is, but of 
what relation it bears to something else. Every 
relation which a thing unknown bears to something 
that is known, may give a relative notion of it ; and 
there are many objects of thought and of discourse 
of which our faculties can give no better than a 
relative notion. 

Having premised these things to explain what is 
meant by a relative notion, it is evident that our 
notion of primary qualities is not of this kind ; we 
know what they are, and not barely what relation 
they bear to something else. 


It is otherwise with secondary qualities. If you 
ask me, what is that quality or modification in a 
rose which I call its smell, I am at a loss to answer 
directly. Upon reflection, I find, that I have a 
distinct notion of the sensation which it produces 
in my mind. But there can be nothing like to this 
sensation in the rose, because it is insentient. The 
quality in the rose is something which occasions 
the sensation in me ; but what that something is, 
I know not. My senses give me no information 
upon this point. The only notion, therefore, my 
senses give is this — that smell in the rose is an un- 
known quality or modification, which is the cause 
or occasion of a sensation which I know well. The 
relation which this unknown quality bears to the 
sensation with which nature hath connected it, is all 
I learn from the sense of smelling ; but this is 
evidently a relative notion. The same reasoning 
will apply to every secondary quality.^ 

§ 6. Of Conception 

Without attempting a definition of this operation 
of the mind, I shall endeavour to explain some 
of its properties ; consider the theories about it ; 
and take notice of some mistakes of philosophers 
concerning it. 

It may be observed that conception enters as an 
ingredient in every operation of the mind. Our 

1 Ibid., pp. 313-314. 

REID 129 

senses cannot give us the belief of any object, 
without giving some conception of it at the same 
time. No man can either remember or reason 
about things of which he hath no conception. When 
we will to exert any of our active powers, there must 
be some conception of what we will to do. There 
can be no desire nor aversion, love nor hatred, 
without some conception of the object. We 
cannot feel pain without conceiving it, though we 
can conceive it without feeling it. These things 
are self-evident. 

In every operation of the mind, therefore, in 
everything we call thought, there must be concep- 
tion. When we analyse the various operations either 
of the understanding or of the will, we shall always 
find this at the bottom, like the caput mortuum of 
the chemists, or the materia prima of the Peripatetics; 
but, though there is no operation of mind without 
conception, yet it may be found naked, detached 
from all others, and then it is called simple appre- 
hension, or the bare conception of a thing. 

As all the operations of our mind are expressed 
by language, every one knows that it is one thing 
to understand what is said, to conceive or apprehend 
its meaning, whether it be a word, a sentence, or a 
discourse ; it is another thing to judge of it, to 
assent or dissent, to be persuaded or moved. The 
first is simple apprehension and may be without the 
last ; but the last cannot be without the first. 



In bare conception there can neither be truth 
nor falsehood, because it neither affirms nor denies. 
Every judgment, and every proposition by which 
judgment is expressed, must be true or false ; and 
the qualities of true and false, in their proper sense, 
can belong to nothing but to judgments, or to pro- 
positions which express judgment. In the bare 
conception of a thing there is no judgment, opinion, 
or belief included, and therefore it cannot be either 
true or false. ^ 

If one should ask. What is meant by conceiving 
a thing ? we should very naturally answer, that it 
is having an image of it in the mind — and perhaps 
we could not explain the word better. This shews 
that conception, and the image of a thing in the 
mind, are synonymous expressions. The image in 
the mind, therefore, is not the object of conception, 
nor is it any effect produced by conception as a 
cause. It is conception itself. That very mode of 
thinking which we call conception, is by another 
name called an image in the mind. 

Nothing more readily gives the conception of a 
thing than the seeing an image of it. Hence, by 
a figure common in language, conception is called 
an image of the thing conceived. But to shew that 
it is not a real but a metaphorical image, it is called 
an image in the mind. We know nothing that is 
properly in the mind but thought ; and, when 

^ Ibid., pp. 360-361. 

REID 131 

anything else is said to be in the mind, the ex- 
pression must be figurative, and signify some kind 
of thought.^ 

Imagination, when it is distinguished from 
conception, seems to me to signify one species of 
conception — to wit, the conception of visible 
objects. Thus, in a mathematical proposition, I 
imagine the figure, and I conceive the demonstra- 
tion ; it would not, I think, be improper to say, I 
conceive both ; but it would not be so proper to 
say, I imagine the demonstration. ^ 

The last property I shall mention of this faculty, 
is that which essentially distinguishes it from every 
other power of the mind ; and it is, that it is not 
employed solely about things which have existence. 
I can conceive a winged horse or a centaur, as easily 
and as distinctly as I can conceive a man whom I 
have seen. Nor does this distinct conception incline 
my judgment in the least to the belief that a winged 
horse or a centaur ever existed. 

It is not so with the other operations of our 
minds. They are employed about real existences, 
and carry with them the belief of their objects. 
When I feel pain, I am compelled to believe that 
the pain that I feel has a real existence. When 
I perceive any external object, my belief of the 
real existence of the object is irresistible. When I 
distinctly remember any event, though that event 

1 Ihid., p. 363. 2 ii)id,^ pp. 365-366. 


may not now exist, I can have no doubt but it did 
exist. That consciousness which we have of the 
operations of our own minds, implies a belief of the 
real existence of those operations. 

Thus we see, that the powers of sensation, of 
perception, of memory, and of consciousness, are 
all employed solely about objects that do exist, or 
have existed. But conception is often employed 
about objects that neither do, nor did, nor will 
exist. This is the very nature of this faculty, that 
its object, though distinctly conceived, may have 
no existence. Such an object we call a creature of 
imagination ; but this creature never was created.^ 

§7. Of Judgment 

First, Judgment is an act of the mind, specifically 
different from simple apprehension, or the bare 
conception of a thing. It would be unnecessary 
to observe this, if some philosophers had not been 
led by their theories to a contrary opinion. 

Although there can be no judgment without a 
conception of the things about which we judge, yet 
conception may be without any judgment. Judg- 
ment can be expressed by a proposition only, and 
a proposition is a complete sentence ; but simple 
apprehension may be expressed by a word or words, 
which make no complete sentence. When simple 
apprehension is employed about a proposition, 

1 Ibid., p. 368. 

REID 133 

every man knows that it is one thing to apprehend 
a proposition — that is, to conceive what it means — 
but it is quite another thing to judge it to be true 
or false. 

It is self-evident that every judgment must be 
either true or false ; but simple apprehension, or 
conception, can neither be true nor false, as was 
shewn before. 

One judgment may be contradictory to another ; 
and it is impossible for a man to have two judgments 
at the same time, which he perceives to be contra- 
dictory. But contradictory propositions may be 
conceived at the same time without any difficulty. 
That the sun is greater than the earth, and that the 
sun is not greater than the earth, are contradictory 
propositions. He that apprehends the meaning of 
one, apprehends the meaning of both. But it is 
impossible for him to judge both to be true at the 
same time. He knows that, if the one is true, the 
other must be false. For these reasons, I hold it to 
be certain that judgment and simple apprehension 
are acts of the mind specifically different. 

Secondly, There are notions or ideas that ought to 
be referred to the faculty of judgment as their 
source ; because, if we had not that faculty, they 
could not enter into our minds ; and to those that 
have that faculty, and are capable of reflecting upon 
its operations, they are obvious and familiar. 

Among these we may reckon the notion of judg- 


ment itself; the notions of a proposition — of its 
subject, predicate, and copula ; of affirmation and 
negation, of true and false ; of knowledge, belief, 
disbelief, opinion, assent, evidence. From no source 
could we acquire these notions, but from reflecting 
upon our judgments. Relations of things make one 
great class of our notions or ideas ; and we cannot 
have the idea of any relation without some exercise 
of judgment, as will appear afterwards. 

Thirdly, In persons come to years of under- 
standing, judgment necessarily accompanies all 
sensation, perception by the senses, consciousness, 
and memory, but not conception. 

I restrict this to persons come to the years of 
understanding, because it may be a question, 
whether infants, in the first period of life, have any 
judgment or belief at all. The same question may 
be put with regard to brutes and some idiots. This 
question is foreign to the present subject ; and I 
say nothing here about it, but speak only of persons 
who have the exercise of judgment. 

In them it is evident that a man who feels pain, 
judges and believes that he is really pained. The 
man who perceives an object, believes that it exists, 
and is what he distinctly perceives it to be ; nor is it 
in his power to avoid such judgment. And the Hke 
may be said of memory, and of consciousness. 
Whether judgment ought to be called a necessary 
concomitant of these operations, or rather a part 

REID 135 

or ingredient of them, I do not dispute ; but it is 
certain that all of them are accompanied with a 
determination that something is true or false, and 
a consequent belief. If this determination be not 
judgment, it is an operation that has got no name ; 
for it is not simple apprehension, neither is it 
reasoning ; it is a mental affirmation or negation ; 
it may be expressed by a proposition affirmative or 
negative, and it is accompanied with the firmest 
belief. These are the characteristics of judgment ; 
and I must call it judgment, till I can find another 
name to it. 

The judgments we form are either of things 
necessary, or of things contingent. That three 
times three is nine, that the whole is greater than a 
part, are judgments about things necessary. Our 
assent to such necessary propositions is not grounded 
upon any operation of sense, of memory, or of con- 
sciousness, nor does it require their concurrence ; 
it is unaccompanied by any other operation but 
that of conception, which must accompany all 
judgment ; we may therefore call this judgment 
of things necessary pure judgment. Our judgment 
of things contingent must always rest upon some 
other operation of the mind, such as sense, or 
memory, or consciousness, or credit in testimony, 
which is itself grounded upon sense. 

That I now write upon a table covered with green 
cloth, is a contingent event, which I judge to be most 


undoubtedly true. My judgment is grounded upon 
my perception, and is a necessary concomitant or 
ingredient of my perception. That I dined with 
such a company yesterday, I judge to be true, 
because I remember it ; and my judgment neces- 
sarily goes along with this remembrance, or makes 
a part of it. 

There are many forms of speech in common 
language which shew that the senses, memory and 
consciousness, are considered as judging faculties. 
We say that a man judges of colours by his eye, of 
sounds by his ear. We speak of the evidence of 
sense, the evidence of memory, the evidence of 
consciousness. Evidence is the ground of judgment; 
and when we see evidence, it is impossible not to 

When we speak of seeing or remembering any- 
thing, we, indeed, hardly ever add that we judge 
it to be true. But the reason of this appears to be, 
that such an addition would be mere superfluity of 
speech, because every one knows that what I see 
or remember, I must judge to be true, and cannot 
do otherwise. 

And, for the same reason, in speaking of any- 
thing that is self-evident or strictly demonstrated, 
we do not say that we judge it to be true. This 
would be superfluity of speech, because every man 
knows that we must judge that to be true which we 
hold self-evident or demonstrated. 

REID 137 

When you say you saw such a thing, or that 
you distinctly remember it, or when you say of 
any proposition that it is self-evident, or strictly 
demonstrated, it would be ridiculous after this 
to ask whether you judge it to be true ; nor would 
it be less ridiculous in you to inform us that you do. 
It would be a superfluity of speech of the same kind 
as if, not content with saying that you saw such 
an object, you should add that you saw it with 
your eyes. 

There is, therefore, good reason why, in speaking 
or writing, judgment should not be expressly men- 
tioned, when all men know it to be necessarily 
implied ; that is, when there can be no doubt. In 
such cases, we barely mention the evidence. But 
when the evidence mentioned leaves room for doubt, 
then, without any superfluity or tautology, we 
say we judge the thing to be so, because this is not 
implied in what was said before. A woman with 
child never says, that, going such a journey, she 
carried her child along with her. We know that, 
while it is in her womb, she must carry it along with 
her. There are some operations of mind that may 
be said to carry judgment in their womb, and can 
no more leave it behind than the pregnant woman 
can leave her child. Therefore, in speaking of 
such operations, it is not expressed.^ 

A fourth observation is, that some exercise of 

^ Ibid., pp. 414-415, 


judgment is necessary in the formation of all 
abstract and general conceptions, whether more 
simple or more complex ; in dividing, in defining, 
and, in general, in forming all clear and distinct 
conceptions of things, which are the only fit 
materials of reasoning. 

These operations are allied to each other, and 
therefore I bring them under one observation. 
They are more allied to our rational nature than 
those mentioned in the last observation, and there- 
fore are considered by themselves. 

That I may not be mistaken, it may be observed 
that I do not say that abstract notions, or other 
accurate notions of things, after they have been 
formed, cannot be barely conceived without any 
exercise of judgment about them. I doubt not 
that they may : but what I say is, that, in their 
formation in the mind at first, there must be some 
exercise of judgment. 

It is impossible to distinguish the different 
attributes belonging to the same subject, without 
judging that they are really different and dis- 
tinguishable, and that they have that relation to 
the subject which logicians express, by saying 
that they may be predicated of it. We cannot 
generalise, without judging that the same attri- 
bute does or may belong to many individuals. It 
has been shewn that our simplest general notions 
are formed by these two operations of distinguishing 

REID 139 

and generalising ; judgment therefore is exercised 
in forming the simplest general notions. 

In those that are more complex, and which have 
been shewn to be formed by combining the more 
simple, there is another act of the judgment re- 
quired ; for such combinations are not made at 
random, but for an end ; and judgment is employed 
in fitting them to that end. We form complex 
general notions for conveniency of arranging our 
thoughts in discourse and reasoning ; and, there- 
fore, of an infinite number of combinations that 
might be formed, we choose only those that are 
useful and necessary. 

I add in general, that, without some degree of 
judgment, we can form no accurate and distinct 
notions of things ; so that one province of judgment 
is, to aid us in forming clear and distinct concep- 
tions of things, which are the only fit materials for 

This will probably appear to be a paradox to 
philosophers, who have always considered the 
formation of ideas of every kind as belonging to 
simple apprehension ; and that the sole province 
of judgment is to put them together in affirmative 
or negative propositions ; and therefore it requires 
some confirmation. 

First, I think it necessarily follows, from what has 
been already said in this observation. For if, 
without some degree of judgment, a man can 


neither distinguish, nor divide, nor define, nor form 
any general notion, simple or complex, he surely, 
without some degree of judgment, cannot have in 
his mind the materials necessary to reasoning. 

There cannot be any proposition in language 
which does not involve some general conception. 
The proposition, that I exist, which Des Cartes 
thought the first of all truths, and the foundation 
of all knowledge, cannot be conceived without the 
conception of existence, one of the most abstract 
general conceptions. A man cannot believe his 
own existence, or the existence of anything he sees 
or remembers, until he has so much judgment as 
to distinguish things that really exist from things 
which are only conceived. He sees a man six feet 
high ; he conceives a man sixty feet high : he 
judges the first object to exist, because he sees it ; 
the second he does not judge to exist, because he 
only conceives it. Now, I would ask, Whether he 
can attribute existence to the first object, and not 
to the second, without knowing what existence 
means ? It is impossible. 

How early the notion of existence enters into the 
mind, I cannot determine ; but it must certainly 
be in the mind as soon as we can affirm of anything, 
with understanding, that it exists. 

In every other proposition, the predicate, at 
least, must be a general notion — a predicable and 
an universal being one and the same. Besides this, 

REID 141 

every proposition either affirms or denies. And no 
man can have a distinct conception of a proposition, 
who does not understand distinctly the meaning 
of affirming or denying. But these are very 
general conceptions, and, as was before observed, 
are derived from judgment, as their source and 
origin. 1 

The necessity of some degree of judgment in 
forming accurate and distinct notions of things will 
farther appear, if we consider attentively what 
notions we can form, without any aid of judgment, 
of the objects of sense, of the operations of our own 
minds, or of the relations of things. 

To begin with the objects of sense. It is acknow- 
ledged, on all hands, that the first notions we have 
of sensible objects are got by the external senses 
only, and probably before judgment is brought 
forth ; but these first notions are neither simple, nor 
are they accurate and distinct : they are gross 
and indistinct, and, like the chaos, a rudis in- 
digestaque moles. Before we can have any distinct 
notion of this mass, it must be analysed ; the hetero- 
geneous parts must be separated in our conception, 
and the simple elements, which before lay hid in 
the common mass, must first be distinguished, and 
then put together into one whole. 

In this way it is that we form distinct notions 
even of the objects of sense ; but this process of 

^ Ibid., pp. 416-417, 


analysis and composition, by habit, becomes so 
easy, and is performed so readily, that we are apt 
to overlook it, and to impute the distinct notion 
we have formed of the object to the senses alone ; 
and this we are the more prone to do because, 
when once we have distinguished the sensible 
qualities of the object from one another, the sense 
gives testimony to each of them. 

If we should apply this reasoning to more com- 
plex objects of sense, the conclusion would be still 
more evident. A dog may be taught to turn a jack, 
but he can never be taught to have a distinct 
notion of a jack. He sees every part as well 
as a man ; but the relation of the parts to one 
another and to the whole, he has not judgment to 

A distinct notion of an object, even of sense, is 
never got in an instant ; but the sense performs 
its office in an instant. Time is not required to 
see it better, but to analyse it, to distinguish the 
different parts, and their relation to one another 
and to the whole. 

Hence it is that, when any vehement passion 
or emotion hinders the cool application of judg- 
ment, we get no distinct notion of an object, even 
though the sense be long directed to it. A man who 
is put into a panic, by thinking he sees a ghost, 
may stare at it long without having any distinct 
notion of it ; it is his understanding, and not 

REID 143 

his sense, that is disturbed by his horror. If he 
can lay that aside, judgment immediately enters 
upon its office, and examines the length and breadth, 
the colour, and figure, and distance of the object. 
Of these, while his panic lasted, he had no distinct 
notion, though his eyes were open all the time. 

When the eye of sense is open, but that of judg- 
ment shut by a panic, or any violent emotion that 
engrosses the mind, we see things confusedly, and 
probably much in the same manner that brutes 
and perfect idiots do, and infants before the use 
of judgment. 

Having said so much of the notions we get from 
the senses alone of the objects of sense, let us next 
consider what notions we can have from conscious- 
ness alone of the operations of our minds. 

Mr Locke very properly calls consciousness an 
internal sense. It gives the like immediate know- 
ledge of things in the mind — that is, of our own 
thoughts and feelings — as the senses give us of 
things external. There is this difference, however, 
that an external object may be at rest, and the 
sense may be employed about it for some time. 
But the objects of consciousness are never at rest : 
the stream of thought flows like a river, without 
stopping a moment ; the whole train of thought 
passes in succession under the eye of consciousness, 
which is always employed about the present. But 
is it consciousness that analyses complex operations. 


distinguishes their different ingredients, and com- 
bines them in distinct parcels under general names ? 
This surely is not the work of consciousness, nor can 
it be performed without reflection, recollecting and 
judging of what we were conscious of, and dis- 
tinctly remember. This reflection does not appear 
in children. Of all the powers of the mind, it seems 
to be of the latest growth, whereas consciousness 
is coeval with the earliest. 

Consciousness, being a kind of internal sense, 
can no more give us distinct and accurate notions 
of the operations of our minds, than the external 
senses can give of external objects. Reflection upon 
the operations of our minds is the same kind of 
operation with that by which we form distinct 
notions of external objects. They differ not in 
their nature, but in this only, that one is employed 
about external, and the other about internal 
objects ; and both may, with equal propriety, be 
called reflection. 

Mr Locke has restricted the word reflection to 
that which is employed about the operations of our 
minds, without any authority, as I think, from 
custom, the arbiter of language. For, surely, I 
may reflect upon what I have seen or heard, as 
well as upon what I have thought. The word, in 
its proper and common meaning, is equally applic- 
able to objects of sense, and to objects of conscious- 
ness. He has likewise confounded reflection with 

REID 145 

consciousness, and seems not to have been aware 
that they are different powers, and appear at very 
different periods of life. 

If that eminent philosopher had been aware of 
these mistakes about the meaning of the word 
reflection, he would, I think, have seen that, as it 
is by reflection upon the operations of our own minds 
that we can form any distinct and accurate notions 
of them, and not by consciousness without reflec- 
tion, so it is by reflection upon the objects of sense, 
and not by the senses without reflection, that we 
can form distinct .notions of them. Reflection 
upon anything, whether external or internal, makes 
it an object of our intellectual powers, by which we 
survey it on all sides, and form such judgments 
about it as appear to be just and true. 

I proposed, in the third place, to consider our 
notions of the relations of things : and here I 
think, that, without judgment, we cannot have any 
notion of relations. 

There are two ways in which we get the notion 
of relations. The first is, by comparing the related 
objects, when we have before had the conception of 
both. By this comparison, we perceive the rela- 
tion, either immediately, or by a process of reason- 
ing. That my foot is longer than my finger, I 
perceive immediately ; and that three is the half of 
six. This immediate perception is immediate and 
intuitive judgment. That the angles at the base 



of an isosceles triangle are equal, I perceive by a 
process of reasoning, in which it will be acknow- 
ledged there is judgment. 

Another way in which we get the notion of 
relations (which seems not to have occurred to Mr 
Locke) is, when, by attention to one of the related 
objects, we perceive or judge that it must, from its 
nature, have a certain relation to something else, 
which before, perhaps, we never thought of ; and 
thus our attention to one of the related objects 
produces the notion of a correlate, and of a certain 
relation between them. 

Thus, when I attend to colour, figure, weight, I 
cannot help judging these to be qualities which 
cannot exist without a subject ; that is, something 
which is coloured, figured, heavy. If I had not 
perceived such things to be qualities, I should 
never have had any notion of their subject, or of 
their relation to it. 

By attending to the operations of thinking, 
memory, reasoning, we perceive or judge that there 
must be something which thinks, remembers, and 
reasons, which we call the mind. When we attend 
to any change that happens in Nature, judgment 
informs us that there must be a cause of this change, 
which had power to produce it ; and thus we get 
the notions of cause and effect, and of the relation 
between them. When we attend to body, we per- 
ceive that it cannot exist without space ; hence we 

REID 147 

get the notion of space (which is neither an object 
of sense nor of consciousness), and of the relation 
which bodies have to a certain portion of unHmited 
space, as their place. 

I apprehend, therefore, that all our notions of 
relations may more properly be ascribed to judgment 
as their source and origin, than to any other power 
of the mind. We must first perceive relations by 
our judgment, before we can conceive them with- 
out judging of them ; as we must first perceive 
colours by sight, before we can conceive them with- 
out seeing them. I think Mr Locke, when he comes 
to speak of the ideas of relations, does not say that 
they are ideas of sensation or reflection, but only 
that they terminate in, and are concerned about, 
ideas of sensation or reflection. 

The notions of unity and number are so abstract, 
that it is impossible they should enter into the mind 
until it has some degree of judgment. We see with 
what difficulty, and how slowly, children learn to 
use, with understanding, the names even of small 
numbers, and how they exult in this acquisition 
when they have attained it. Every number is 
conceived by the relation which it bears to unity, 
or to known combinations of units ; and upOn 
that account, as well as on account of its abstract 
nature, all distinct notions of it require some 
degree of judgment. 

In its proper place, I shall have occasion to shew 


that judgment is an ingredient in all determina- 
tions of taste, in all moral determinations, and in 
many of our passions and affections. So that this 
operation, after we come to have any exercise of 
judgment, mixes with most of the operations of 
our minds, and, in analysing them, cannot be over- 
looked without confusion and error. ^ 

§ 8. Of Common Sense 

All that is intended in this chapter is to explain 
the meaning of common sense, that it may not be 
treated, as it has been by some, as a new principle, 
or as a word without any meaning. I have en- 
deavoured to shew that sense, in its most common, 
and therefore its most proper meaning, signifies 
judgment, though philosophers often use it in 
another meaning. From this it is natural to think 
that common sense should mean common judgment; 
and so it really does. 

What the precise limits are which divide 
common judgment from what is beyond it on 
the one hand, and from what falls short of it 
on the other, may be difficult to determine ; and 
men may agree in the meaning of the word who 
have different opinions about those limits, or who 
even never thought of fixing them. This is as 
intelligible as, that all Englishmen should mean 
the same thing by the county of York, though 

1 Ibid., pp. 418-421. 

REID 149 

perhaps not a hundredth part of them can point 
out its precise Hmits. 

Indeed, it seems to me, that common sense is as 
unambiguous a word and as well understood as the 
county of York. We find it in innumerable places 
in good writers ; we hear it on innumerable 
occasions in conversation ; and, as far as I am able 
to judge, always in the same meaning. And this 
is probably the reason why it is so seldom defined 
or explained. 

Dr Johnson, in the authorities he gives, to shew 
that the word sense signifies understanding, sound- 
ness of faculties, strength of natural reason, quotes 
Dr Bentley for what may be called a definition of 
common sense, though probably not intended for 
that purpose, but mentioned accidentally : '' God 
hath endowed mankind with power and abilities, 
which we call natural light and reason, and common 
sense." ^ 

It is absurd to conceive that there can be any 
opposition between reason and common sense. 
It is indeed the first-born of Reason ; and, as they 
are commonly joined together in speech and in 
writing, they are inseparable in their nature. 

We ascribe to reason two offices, or two degrees. 
The first is to judge of things self-evident ; the 
second to draw conclusions that are not self- 
evident from those that are. The first of these 

1 Ibid., pp. 422-423. 


is the province, and the sole province, of common 
sense ; and, therefore, it coincides with reason in its 
whole extent, and is only another name for one 
branch or one degree of reason. Perhaps it may be 
said, Why then should you give it a particular 
name, since it is acknowledged to be only a degree 
of reason ? It would be a sufficient answer to this, 
Why do you abolish a name which is to be found 
in the language of all civilized nations, and has 
acquired a right by prescription ? Such an attempt 
is equally foolish and ineffectual. Every wise man 
will be apt to think that a name which is found in all 
languages as far back as we can trace them, is not 
without some use. 

But there is an obvious reason why this degree 
of reason should have a name appropriated to it ; 
and that is, that, in the greatest part of mankind, 
no other degree of reason is to be found. It is this 
degree that entitles them to the denomination of 
reasonable creatures. It is this degree of reason, 
and this only, that makes a man capable of manag- 
ing his own affairs, and answerable for his conduct 
towards others. There is therefore the best reason 
why it should have a name appropriated to it. 

These two degrees of reason differ in other re- 
spects, which would be sufficient to entitle them to 
distinct names. 

The first is purely the gift of Heaven. And 
where Heaven has not given it, no education can 

REID 151 

supply the want. The second is learned by practice 
and rules, when the first is not wanting. A man who 
has common sense may be taught to reason. But, 
if he has not that gift, no teaching will make him 
able either to judge of first principles or to reason 
from them. 

I have only this farther to observe, that the 
province of common sense is more extensive 
in refutation than in confirmation. A conclusion 
drawn by a train of just reasoning from true 
principles cannot possibly contradict any decision 
of common sense, because truth will always be 
consistent with itself. Neither can such a con- 
clusion receive any confirmation from common 
sense, because it is not within its jurisdiction. 

But it is possible that, by setting out from false 
principles, or by an error in reasoning, a man may 
be led to a conclusion that contradicts the decisions 
of common sense. In this case, the conclusion 
is within the jurisdiction of common sense, though 
the reasoning on which it was grounded be not ; and 
a man of common sense may fairly reject the con- 
clusion without being able to shew the error of the 
reasoning that led to it. 

Thus, if a mathematician, by a process of intricate 
demonstration, in which some false step was made, 
should be brought to this conclusion, that two 
quantities, which are both equal to a third, are 
not equal to each other, a man of common sense, 


without pretending to be a judge of the demonstra- 
tion, is well entitled to reject the conclusion, and to 
pronounce it absurd.^ 

§ 9. The First Principles of Contingent 

It is necessary that the first principles of know- 
ledge be distinguished from other truths, and 
presented to view, that they may be sifted and ex- 
amined on all sides. In order to this end, I shall 
attempt a detail of those I take to be such, and of 
the reasons why I think them entitled to that 

If the enumeration should appear to some re- 
dundant, to others deficient, and to others both — 
if things which I conceive to be first principles, 
should to others appear to be vulgar errors, or to 
be truths which derive their evidence from other 
truths, and therefore not first principles — in these 
things every man must judge for himself. I shall 
rejoice to see an enumeration more perfect in any or 
in all of those respects ; being persuaded that the 
agreement of men of judgment and candour in 
first principles would be of no less consequence to 
the advancement of knowledge in general, than 
the agreement of mathematicians in the axioms of 
geometry has been to the advancement of that 

* Ibid., pp. 425-426. 

REID 153 

The truths that fall within the compass of human 
knowledge, whether they be self-evident, or deduced 
from those that are self-evident, may be reduced 
to two classes. They are either necessary and 
immutable truths, whose contrary is impossible ; or 
they are contingent and mutable, depending upon 
some effect of will and power, which had a beginning, 
and may have an end. 

That a cone is the third part of a cylinder of the 
same base and the same altitude, is a necessary 
truth. It depends not upon the will and power of 
any being. It is immutably true, and the contrary 
impossible. That the sun is the centre about which 
the earth, and the other planets of our system, 
perform their revolutions, is a truth ; but it is not 
a necessary truth. It depends upon the power and 
will of that Being who made the sun and all the 
planets, and who gave them those motions that 
seemed best to him. 

As the minds of men are occupied much more 
about truths that are contingent than about those 
that are necessary, I shall first endeavour to point 
out the principles of the former kind. 

I. First, then, I hold, as a first principle, the 
existence of everything of which I am conscious. 

This, I think, is the only principle of common 
sense that has never directly been called in question. 
It seems to be so firmly rooted in the minds of 
men, as to retain its authority with the greatest 


sceptics. Mr Hume, after annihilating body and 
mind, time and space, action and causation, and 
even his own mind, acknowledges the reality of the 
thoughts, sensations, and passions of which he is 

2. Another first principle, I think, is, That the 
thoughts of which I am conscious, are the thoughts 
of a being which I call myself, my mind, my person. 

The thoughts and feelings of which we are con- 
scious are continually changing, and the thought of 
this moment is not the thought of the last ; but 
something which I call myself, remains under 
this change of thought. This self has the same 
relation to all the successive thoughts I am conscious 
of — they are all my thoughts ; and every thought 
which is not my thought, must be the thought of 
some other person. 

If any man asks a proof of this, I confess I can 
give none ; there is an evidence in the proposition 
itself which I am unable to resist. Shall I think 
that thought can stand by itself without a thinking 
being ? or that ideas can feel pleasure or pain ? 
My nature dictates to me that it is impossible. 

3. Another first principle I take to be — That 
those things did really happen which I distinctly 

This has one of the surest marks of a first principle; 
for no man ever pretended to prove it, and yet no 
man in his wits calls it in question : the testimony 

REID 155 

of memory, like that of consciousness, is immediate ; 
it claims our assent upon its own authority. 

4. Another first principle is, Our own personal 
identity and continued existence, as far back as 
we remember anything distinctly. 

This we know immediately, and not by reasoning. 
It seems, indeed, to be a part of the testimony of 
memory. Everything we remember has such a 
relation to ourselves as to imply necessarily our 
existence at the time remembered. 

5. Another first principle is, That those things 
do really exist which we distinctly perceive by our 
senses, and are what we perceive them to be. 

It is too evident to need proof, that all men are 
by nature led to give implicit faith to the distinct 
testimony of their senses, long before they are 
capable of any bias from prejudices of education 
or of philosophy. 

6. Another first principle, I think, is. That we 
have some degree of power over our actions, and the 
determinations of our will. 

All power must be derived from the fountain of 
power, and of every good gift. Upon His good 
pleasure its continuance depends, and it is always 
subject to His control. 

Beings to whom God has given any degree of 
power, and understanding to direct them to the 
proper use of it, must be accountable to their 
Maker. But those who are intrusted with no power 


can have no account to make ; for all good conduct 
consists in the right use of power ; all bad conduct 
in the abuse of it. 

7. Another first principle is — That the natural 
faculties, by which we distinguish truth from error, 
are not fallacious. If any man should demand 
a proof of this, it is impossible to satisfy him. For, 
suppose it should be mathematically demonstrated, 
this would signify nothing in this case ; because, to 
judge of a demonstration, a man must trust his facul- 
ties, and take for granted the very thing in question. 

8. Another first principle relating to existence, is, 
That there is life and intelligence in our fellow-men 
with whom we converse. 

9. Another first principle I take to be, that 
certain features of the countenance, sounds of the 
voice, and gestures of the body, indicate certain 
thoughts and dispositions of mind. 

10. Another first principle appears to me to be — 
That there is a certain regard due to human testi- 
mony in matters of fact, and even to human 
authority in matters of opinion. 

11. There are many events depending upon the 
will of man, in which there is a self-evident pro- 
bability, greater or less, according to circumstances. 

12. The last principle of contingent truths I 
mention is. That, in the phaenomena of nature, what 
is to be will probably be like to what has been in 
similar circumstances. 

REID 157 

We must have this conviction as soon as we are 
capable of learning anything from experience ; for 
all experience is grounded upon a belief that the 
future will be like the past. Take away this 
principle, and the experience of an hundred years 
makes us no wiser with regard to what is to come. 

This is one of those principles which, when we 
grow up and observe the course of nature, we can 
confirm by reasoning. We perceive that Nature is 
governed by fixed laws, and that, if it were not so, there 
could be no such thing as prudence in human conduct ; 
there would be no fitness in any means to promote 
an end ; and what, on one occasion, promoted it, 
might as probably, on another occasion, obstruct it. 

But the principle is necessary for us before we are 
able to discover it by reasoning, and therefore is 
made a part of our constitution, and produces its 
effects before the use of reason. 

I do not at all affirm, that those I have mentioned 
are all the first principles from which we may 
reason concerning contingent truths. Such enum- 
erations, even when made after much reflection, are 
seldom perfect.^ 

§ 10. First Principles of Necessary Truths 

About most of the first principles of necessary 
truths there has been no dispute, and therefore it is 

^ Ibid., pp. 441-452. (In reprinting this and the following 
section some passages have been silently omitted.) 


the less necessary to dwell upon them. It will be 
sufficient to divide them into different classes ; to 
mention some, by way of specimen, in each class ; 
and to make some remarks on those of which the 
truth has been called in question. 

They may, I think, most properly be divided 
according to the sciences to which they belong. 

1. There are some first principles that may be 
called grammatical : such as. That every adjective 
in a sentence must belong to some substantive 
expressed or understood ; that every complete 
sentence must have a verb. 

2. There are logical axioms : such as, That any 
contexture of words, which does not make a pro- 
position, is neither true nor false ; That every 
proposition is either true or false ; That no proposi- 
tion can be both true and false at the same time ; 
That reasoning in a circle proves nothing ; That 
whatever may be truly affirmed of a genus, may 
be truly affirmed of all the species, and all the 
individuals belonging to that genus. 

3. Every one knows there are mathematical 
axioms. Mathematicians have, from the days of 
Euclid, very wisely laid down the axioms or first 
principles on which they reason. And the effect which 
this appears to have had upon the stability and happy 
progress of this science, gives no small encouragement 
to attempt to lay the foundation of other sciences 
in a similar manner, as far as we are able. 

REID 159 

4. I think there are axioms, even in matters of 
taste. Notwithstanding the variety found among 
men in taste, there are, I apprehend, some common 
principles, even in matters of this kind. I never 
heard of any man who thought it a beauty in a 
human face to want a nose, or an eye, or to have 
the mouth on one side. 

That an unjust action has more demerit than an 
ungenerous one : That a generous action has more 
merit than a merely just one : That no man ought to 
be blamed for what it was not in his power to hinder : 
That we ought not to do to others what we would 
think unjust or unfair to be done to us in like 
circumstances. These are moral axioms, and many 
others might be named which appear to me to have 
no less evidence than those of mathematics. 

Some perhaps may think that our determinations, 
either in matters of taste or in morals, ought not 
to be accounted necessary truths : That they are 
grounded upon the constitution of that faculty 
which we call taste, and of that which we call the 
moral sense or conscience; which faculties might 
have been so constituted as to have given deter- 
minations different, or even contrary to those 
they now give : That, as there is nothing sweet 
or bitter in itself, but according as it agrees or 
disagrees with the external sense called taste ; so 
there is nothing beautiful or ugly in itself, but 
according as it agrees or disagrees with the in- 


ternal sense, which we also call taste ; and nothing 
morally good or ill in itself, but according as it 
agrees or disagrees with our moral sense. 

This indeed is a system, with regard to morals 
and taste, which hath been supported in modern 
times by great authorities. And if this system be 
true, the consequence must be, that there can be 
no principles, either of taste or of morals, that are 
necessary truths. For, according to this system, 
all our determinations, both with regard to matters 
of taste, and with regard to morals, are reduced 
to matters of fact — I mean to such as these, that 
by , our constitution we have on such occasions 
certain agreeable feelings, and on other occasions 
certain disagreeable feelings. 

But I cannot help being of a contrary opinion, 
being persuaded that a man who determined that 
polite behaviour has great deformity, and that 
there is great beauty in rudeness and ill-breeding, 
would judge wrong, whatever his feelings were. 

In like manner, I cannot help thinking that a man 
who determined that there is more moral worth in 
cruelty, perfidy, and injustice, than in generosity, 
justice, prudence, and temperance, would judge 
wrong, whatever his constitution was. 

And, if it be true that there is judgment in our 
determinations of taste and of morals, it must be 
granted that what is true or false in morals, or in 
matters of taste, is necessarily so. For this reason. 

REID i6i 

I have ranked the first principles of morals and of 
taste under the class of necessary truths. 

6. The last class of first principles I shall mention, 
we may call metaphysical. 

I shall particularly consider three of these, 
because they have been called in question by 
Mr Hume. 

The first is. That the qualities which we perceive 
by our senses must have a subject, which we call 
body, and that the thoughts we are conscious of 
must have a subject, which we call mind. 

The second metaphysical principle I mention is — 
That whatever begins to exist, must have a cause 
which produced it. 

The last metaphysical principle I mention, which 
is opposed by the same author, is, That design and 
intelligence in the cause may be inferred, with 
certainty, from marks or signs of it in the effect. ^ 


§ I. Of Benevolent Affection in General 

There are various principles of action in man, 
which have persons for their immediate object, 
and imply, in their very nature, our being well or 
ill affected to some person, or, at least, to some 
animated being. 

Such principles, I shall call by the general name 

1 Ibid., pp. 452-457- 



of affections, whether they dispose us to do good 
or hurt to others. 

The principles which lead us immediately to 
desire the good of others, and those that lead us to 
desire their hurt, agree in this, that persons, and 
not things, are their immediate object. Both 
imply our being some way affected towards the 
person. They ought, therefore, to have some 
common name to express what is common in their 
nature ; and I know no name more proper for this 
than affection. 

Taking affection, therefore, in this extensive 
sense, our affections are very naturally divided into 
benevolent and malevolent, according as they 
imply our being well or ill affected towards their 

There are some things common to all benevolent 
affections, others wherein they differ. 

They differ both in the feeling or sensation, 
which is an ingredient in all of them, and in the 
objects to which they are directed. 

They all agree in two things — to wit. That the 
feeling which accompanies them is agreeable ; and. 
That they imply a desire of good and happiness to 
their object. 

A thing may be desired either on its own account, 
or as the means in order to something else. That 
only can properly be called an object of desire, 
which is desired upon its own account ; and it is 

REID 163 

only such desires that I call principles of action. 
When anything is desired as the means only, there 
must be an end for which it is desired ; and the 
desire of the end is, in this case, the principle of 
action. The means are desired only as they tend 
to that end ; and, if different, or even contrary 
means, tended to the same end, they would be 
equally desired. 

On this account, I consider those affections only 
as benevolent, where the good of the object is 
desired ultimately, and not as the means only, in 
order to something else. 

To say that we desire the good of others, only in 
order to procure some pleasure or good to ourselves, 
is to say that there is no benevolent affection in 
human nature. 

This, indeed, has been the opinion of some philo- 
sophers, both in ancient and in later times. I 
intend not to examine this opinion in this place, 
conceiving it proper to give that view of the prin- 
ciples of action in man, which appears to me to 
be just, before I examine the systems wherein they 
have been mistaken or misrepresented. 

I observe only at present, that it appears as 
unreasonable to resolve all our benevolent affections 
into self-love, as it would be to resolve hunger and 
thirst into self-love. 

These appetites are necessary for the preservation 
of the individual. Benevolent affections are no 


less necessary for the preservation of society among 
men, without which man would become an easy 
prey to the beasts of the field. 

We are placed in this world by the Author of 
our being, surrounded with many objects that are 
necessary or useful to us, and with many that may 
hurt us. We are led, not by reason and self-love 
only, but by many instincts, and appetites, and 
natural desires to seek the former and to avoid the 

But of all the things of this world, man may be 
the most useful or the most hurtful to man. Every 
man is in the power of every man with whom he 
lives. Every man has power to do much good to 
his fellow-men, and to do more hurt. 

We cannot live without the society of men ; and 
it would be impossible to live in society, if men were 
not disposed to do much of that good to men, and 
but little of that hurt, which it is in their power 
to do. 

But how shall this end, so necessary to the 
existence of human society, and consequently to 
the existence of the human species, be accomplished ? 

If we judge from analogy, we must conclude that 
in this, as in other parts of our conduct, our rational 
principles are aided by principles of an inferior 
order, similar to those by which many brute 
animals live in society with their species ; and that, 
by means of such principles, that degree of regularity 

REID 165 

is observed, which we find in all societies of men, 
whether wise or foolish, virtuous or vicious. 

The benevolent affections planted in human 
nature appear therefore no less necessary for the 
preservation of the human species, than the appe- 
tites of hunger and thirst. ^ 

§ 2. There are Rational Principles of 
Action in Man 

Mechanical principles of action produce their 
effect without any will or intention on our part. We 
may, by a voluntary effort, hinder the effect ; but, 
if it be not hindered by will and effort, it is produced 
without them. 

Animal principles of action require intention and 
will in their operation, but not judgment. They 
are, by ancient moralists, very properly called 
ccBCCB cupidines, blind desires. 

Having treated of these two classes, I proceed 
to the third — the rational principles of action in 
man ; which have that name, because they can have 
no existence in beings not endowed with reason, 
and, in all their exertions, require, not only inten- 
tion and will, but judgment or reason. 

That talent which we call Reason, by which men 
that are adult and of a sound mind are distinguished 

^ " Essays on the Active Powers of Man," Works, vol. ii. 
PP- 558-560. (In reprinting this and the following sections 
on Morals several passages have been silently omitted.) 


from brutes, idiots, and infants, has, in all ages, 
among the learned and unlearned, been conceived 
to have two offices — to regulate our belief, and to 
regulate our actions and conduct. 

Whatever we believe, we think agreeable to 
reason, and, on that account, yield our assent to 
it. Whatever we disbelieve, we think contrary 
to reason, and, on that account, dissent from it. 
Reason, therefore, is allowed to be the principle by 
which our belief and opinions ought to be regulated. 

But reason has been no less universally con- 
ceived to be a principle by which our actions ought 
to be regulated. 

To act reasonably, is a phrase no less common 
in all languages, than to judge reasonably. We 
immediately approve of a man's conduct, when it 
appears that he had good reason for what he did. 
And every action we disapprove, we think unreason- 
able, or contrary to reason. 

A way of speaking so universal among men, 
common to the learned and the unlearned in all 
nations and in all languages, must have a meaning. 
To suppose it to be words without meaning, is to 
treat, with undue contempt, the common sense of 

Supposing this phrase to have a meaning, we may 
consider in what way reason may serve to regulate 
human conduct, so that some actions of men are to be 
denominated reasonable, and others unreasonable. 

REID 167 

I take it for granted, that there can be no exercise 
of Reason without Judgment, nor, on the other hand, 
any judgment of things, abstract and general, 
without some degree of reason. 

If, therefore, there be any principles of action 
in the human constitution, which, in their nature, 
necessarily imply such judgment, they are the 
principles which we may call rational, to distinguish 
them from animal principles, which imply desire 
and will, but not judgment. 

Every deliberate human action must be done either 
as the means, or as an end ; as the means to some end, 
to which it is subservient, or as an end, for its own 
sake, and without regard to anything beyond it. 

That it is a part of the office of reason to deter- 
mine what are the proper means to any end which 
we desire, no man ever denied. But some philo- 
sophers, particularly Mr Hume, think that it is no 
part of the office of reason to determine the ends we 
ought to pursue, or the preference due to one end 
above another. This, he thinks, is not the office 
of reason, but of taste or feeling. 

If this be so, reason cannot, with any propriety, 
be called a principle of action. Its office can only 
be to minister to the principles of action, by dis- 
covering the means of their gratification. Accord- 
ingly, Mr Hume maintains, that reason is no prin- 
ciple of action ; but that it is, and ought to be, the 
servant of the passions. 


I shall endeavour to shew that, among the various 
ends of human actions, there are some, of which, 
without reason, we could not even form a concep- 
tion ; and that, as soon as they are conceived, a 
regard to them is, by our constitution, not only a 
principle of action, but a leading and governing 
principle, to which all our animal principles are 
subordinate, and to which they ought to be subject. 

These I shall call rational principles ; because 
they can exist only in beings endowed with reason, 
and because, to act from these principles, is what 
has always been meant by acting according to 

The ends of human actions I have in view, are 
two — to wit. What is good for us upon the whole, 
and What appears to he our duty. They are very 
strictly connected, lead to the same course of con- 
duct, and co-operate with each other ; and, on that 
account, have commonly been comprehended under 
one name — that of reason. But, as they may be 
disjoined, and are really distinct principles of 
action, I shall consider them separately.^ 

§3. Of Regard to Our Good on the Whole 

It will not be denied that man, when he comes 
to years of understanding, is led, by his rational 
nature, to form the conception of what is good for 
him upon the whole. 

' Jhid., pp. 579-580 

REID 169 

How early in life this general notion of good enters 
into the mind, I cannot pretend to determine. It 
is one of the most general and abstract notions 
we form. 

Whatever makes a man more happy or more 
perfect, is good, and is an object of desire as soon 
as we are capable of forming the conception of it. 
The contrary is ill, and is an object of aversion. 

In the first part of life, we have many enjoyments 
of various kinds ; but very similar to those of 

They consist in the exercise of our senses and 
powers of motion, the gratification of our appetites, 
and the exertions of our kind affections. These are 
chequered with many evils of pain, and fear, and 
disappointment, and sympathy with the sufferings 
of others. 

But the goods and evils of this period of life are 
of short duration, and soon forgot. The mind, 
being regardless of the past, and unconcerned 
about the future, we have then no other measure of 
good but the present desire ; no other measure of 
evil but the present aversion. 

Every animal desire has some particular and 
present object, and looks not beyond that object 
to its consequences, or to the connections it may 
have with other things. 

The present object, which is most attractive, or 
.excites the strongest desire, determines the choice. 


whatever be its consequences. The present evil 
that presses most, is avoided, though it should be 
the road to a greater good to come, or the only way 
to escape a greater evil. This is the way in which 
brutes act, and the way in which men must act, till 
they come to the use of reason. 

As we grow up to understanding, we extend our 
view both forward and backward. We reflect 
upon what is past, and, by the lamp of experience, 
discern what will probably happen in time to come. 
We find that many things which we eagerly desired, 
were too dearly purchased, and that things grievous 
for the present, like nauseous medicines, may be 
salutary in the issue. 

We learn to observe the connexions of things, 
and the consequences of our actions ; and, taking 
an extended view of our existence, past, present, 
and future, we correct our first notions of good and 
ill, and form the conception of what is good or ill 
upon the whole ; which must be estimated, not 
from the present feeling, or from the present animal 
desire or aversion, but from a due consideration 
of its consequences, certain or probable, during the 
whole of our existence. 

That which, taken with all its discoverable 
connexions and consequences, brings more good 
than ill, I call good upon the whole. 

That brute-animals have any conception of this 
good, I see no reason to believe. And it is evident 

REID 171 

that man cannot have the conception of it, till 
reason is so far advanced that he can seriously 
reflect upon the past, and take a prospect of the 
future part of his existence. 

It appears, therefore, that the very conception 
of what is good or ill for us upon the whole, is the 
offspring of reason, and can be only in beings 
endowed with reason. And if this conception give 
rise to any principle of action in man, which he 
had not before, that principle may very properly 
be called a rational principle of action. 

I observe, in the next place — That as soon as we 
have the conception of what is good or ill for us upon 
the whole, we are led, by our constitution, to seek 
the good and avoid the ill ; and this becomes not 
only a principle of action, but a leading or governing 
principle, to which all our animal principles ought 
to be subordinate. 

To prefer a greater good, though distant, to a 
less that is present ; to choose a present evil, in 
order to avoid a greater evil, or to obtain a 
greater good, is, in the judgment of all men, 
wise and reasonable conduct ; and, when a man 
acts the contrary part, all men will acknow- 
ledge that he acts foolishly and unreasonably. 
Nor will it be denied, that, in innumerable cases in 
common life, our animal principles draw us one 
way, while a regard to what is good on the whole, 
draws us the contrary way. Thus the flesh lusteth 


against the spirit, and the spirit against the flesh, 
and these two are contrary. That in every conflict 
of this kind the rational principle ought to prevail, 
and the animal to be subordinate, is too evident 
to need, or to admit of proof. 

Thus, I think, it appears, that, to pursue what 
is good upon the whole, and to avoid what is ill 
upon the whole, is a rational principle of action 
grounded upon our constitution as reasonable 

It appears that it is not without just cause, that 
this principle of action has in all ages been called 
reason, in opposition to our animal principles, which 
in common language are called by the general name 
of the passions. 

The first not only operates in a calm and cool 
manner, like reason, but implies real judgment 
in all its operations. The second — to wit, the 
passions — are blind desires of some particular 
object, without any judgment or consideration, 
whether it be good for us upon the whole, 
or iU. 

It appears also, that the fundamental maxim 
of prudence, and of all good morals — That the 
passions ought, in all cases, to be under the dominion 
of reason — is not only self-evident, when rightly 
understood, but is expressed according to the com- 
mon use and propriety of language.^ 

* Ibid., pp. 580-581, 

REID 173 

§ 4. Of the Notion of Duty, Rectitude, 
Moral Obligation 

A being endowed with the animal principles of 
action only may be capable of being trained to 
certain purposes by discipline, as we see many 
brute-animals are, but would be altogether in- 
capable of being governed by law. 

The subject of law must have the conception 
of a general rule of conduct, which, without some 
degree of reason, he cannot have. He must like- 
wise have a sufficient inducement to obey the law, 
even when his strongest animal desires draw him 
the contrary way. 

This inducement may be a sense of inter est, or a 
sense of duty, or both concurring. 

These are the only principles I am able to con- 
ceive, which can reasonably induce a man to regu- 
late all his actions according to a certain general 
rule or law. They may therefore be justly called 
the rational principles of action, since they can have 
no place but in a being endowed with reason, and 
since it is by them only that man is capable either 
of political or of moral government. 

Without them human life would be like a ship 
at sea without hands, left to be carried by winds 
and tides as they happen. It belongs to the 
rational part of our nature to intend a certain port, 
as the end of the voyage of life ; to take the advan- 


tage of winds and tides when they are favourable, 
and to bear up against them when they are un- 

A sense of interest may induce us to do this, when 
a suitable reward is set before us. But there is a 
nobler principle in the constitution of man, which, 
in many cases, gives a clearer and more certain 
rule of conduct, than a regard merely to interest 
would give, and a principle, without which man 
would not be a moral agent. 

A man is prudent when he consults his real 
interest ; but he cannot be virtuous, if he has no 
regard to duty. 

I proceed now to consider this regard to Duty 
as a rational principle of action in man, and as that 
principle alone by which he is capable either of 
virtue or vice. 

I shall first offer some observations with regard 
to the general notion of duty, and its contrary, or 
of right and wrong in human conduct, and then 
consider, how we come to judge and determine 
certain things in human conduct to be right, and 
others to be wrong. 

With regard to the notion or conception of Duty, 
I take it to be too simple to admit of a logical 

We can define it only by synonymous words or 
phrases, or by its properties and necessary con- 
comitants, as when we say that it is what we ought 

REID 175 

to do — what is fair and honest — what is approvable 
— what every man professes to be the rule of his 
conduct — what all men praise^and, what is in 
itself laudable, though no man should praise it. 

I observe, in the next place. That the notion of 
duty cannot be resolved into that of interest, or 
what is most for our happiness. 

Every man may be satisfied of this who attends 
to his own conceptions, and the language of all 
mankind shews it. When I say. This is my interest, 
I mean one thing ; when I say, It is my duty, I 
mean another thing. And, though the same course 
of action, when rightly understood, may be both 
my duty and my interest, the conceptions are very 
different. Both are reasonable motives to action, 
but quite distinct in their nature. 

I presume it will be granted, that, in every man 
of real worth, there is a principle of honour, a regard 
to what is honourable or dishonourable, very dis- 
tinct from a regard to his interest. It is folly in a 
man to disregard his interest, but to do what is 
dishonourable, is baseness. The first may move 
our pity, or, in some cases, our contempt ; but the 
last provokes our indignation. 

As these two principles are different in their 
nature, and not resolvable into one, so the principle 
of honour is evidently superior in dignity to that 
of interest. 

No man would allow him to be a man of honour 


who should plead his interest to justify what he 
acknowledged to be dishonourable ; but to sacrifice 
interest to honour never costs a blush. 

It likewise will be allowed by every man of honour, 
that this principle is not to be resolved into a regard 
to our reputation among men, otherwise the man of 
honour would not deserve to be trusted in the dark. 
He would have no aversion to lie, or cheat, or 
play the coward, when he had no dread of being 

I take it for granted, therefore, that every man 
of real honour feels an abhorrence of certain actions, 
because they are in themselves base, and feels an 
obligation to certain other actions, because they are 
in themselves what honour requires, and this in- 
dependently of any consideration of interest or 

This is an immediate moral obligation. This 
principle of honour, which is acknowledged by all 
men who pretend to character, is only another name 
for what we call a regard to duty, to rectitude, to 
propriety of conduct. It is a moral obligation 
which obliges a man to do certain things because 
they are right, and not to do other things because 
they are wrong. 

Ask the man of honour why he thinks himself 
obliged to pay a debt of honour ? The very 
question shocks him. To suppose that he needs 
any other inducement to do it but the principle 

REID lyy 

of honour, is to suppose that he has no honour, 
no worth, and deserves no esteem. 

There is, therefore, a principle in man, which, 
when he acts according to it, gives him a conscious- 
ness of worth, and, when he acts contrary to it, a 
sense of demerit. 

From the varieties of education, of fashion, of 
prejudices, and of habits, men may differ much in 
opinion with regard to the extent of this principle, 
and of what it commands and forbids ; but the 
notion of it, as far as it is carried, is the same in all. 
It is that which gives a man real worth, and is the 
object of moral approbation. 

Men of rank call it honour, and too often confine 
it to certain virtues that are thought most essential 
to their rank. The vulgar call it honesty, probity, 
virtue, conscience. Philosophers have given it the 
names of the moral sense, the moral faculty, rectitude. 

If we examine the abstract notion of Duty, or 
Moral Obligation, it appears to be neither any real 
quality of the action considered by itself, nor of 
the agent considered without respect to the action, 
but a certain relation between the one and the other. 

When we say a man ought to do such a thing, the 
ought, which expresses the moral obligation, has a 
respect, on the one hand, to the person who ought ; 
and, on the other, to the action which he ought to 
do. Those two correlates are essential to every 
moral obligation ; take away either, and it has no 



existence. So that, if we seek the place of moral 
obligation among the categories, it belongs to the 
category of relation. 

There are many relations of things, of which we 
have the most distinct conception, without being 
able to define them logically. Equality and pro- 
portion are relations between quantities, which 
every man understands, but no man can define. 

Moral obligation is a relation of its own kind, 
which every man understands, but is, perhaps, 
too simple to admit of logical definition. Like 
all other relations, it may be changed or annihilated 
by a change in any of the two related things — I 
mean the agent or the action. 

Perhaps it may not be improper to point out 
briefly the circumstances, both in the action and 
in the agent, which are necessary to constitute 
moral obligation. The universal agreement of 
men in these, shews that they have one and the 
same notion of it. 

With regard to the action, it must be a voluntary 
action, or prestation of the person obliged, and 
not of another. There can be no moral obligation 
upon a man to be six feet high. Nor can I be under 
a moral obligation that another person should do 
such a thing. His actions must be imputed to 
himself, and mine only to me, either for praise 
or blame. 

I need hardly mention, that a person can be under 

REID 179 

a moral obligation, only to things within the sphere 
of his natural power. 

As to the party obliged, it is evident there can be 
no moral obligation upon an inanimate thing. To 
speak of moral obligation upon a stone or a tree is 
ridiculous, because it contradicts every man's 
notion of moral obligation. 

The person obliged must have understanding and 
will, and some degree of active power. He must 
not only have the natural faculty of understanding, 
but the means of knowing his obligation. An 
invincible ignorance of this destroys all moral 

The opinion of the agent in doing the action gives 
it its moral denomination. If he does a materially 
good action, without any belief of its being good, 
but from some other principle, it is no good action 
in him. And if he does it with the belief of its 
being ill, it is ill in him. 

Thus, if a man should give to his neighbour a 
potion which he really believes will poison him, 
but which, in the event, proves salutary, and does 
much good ; in moral estimation, he is a poisoner, 
and not a benefactor. 

These qualifications of the action and of the agent, 
in moral obligation, are self-evident ; and the agree- 
ment of all men in them shews that all men have 
the same notion, and a distinct notion of moral 


We are next to consider, how we learn to judge 
and determine, that this is right, and that is 

The abstract notion of moral good and ill would 
be of no use to direct our life, if we had not the 
power of applying it to particular actions, and 
determining what is morally good, and what is 
morally ill. 

Some philosophers, with whom I agree, ascribe 
this to an original power or faculty in man, which 
they call the Moral Sense, the Moral Faculty, 

In its dignity it is, without doubt, far superior 
to every other power of the mind ; but there is 
this analogy between it and the external senses, 
That, as by them we have not only the original 
conceptions of the various qualities of bodies, but 
the original judgment that this body has such a 
quality, that such another ; so by our moral 
faculty, we have both the original conceptions of 
right and wrong in conduct, of merit and demerit, 
and the original judgments that this conduct is 
right, that is wrong ; that this character has worth, 
that demerit. 

The testimony of our moral faculty, like that of 
the external senses, is the testimony of nature, and 
we have the same reason to rely upon it. 

The truths immediately testified by the external 
senses are the first principles from which we reason, 

REID i8i 

with regard to the material world, and from which 
all our knowledge of it is deduced. 

The truths immediately testified by our moral 
faculty, are the first principles of all moral reasoning, 
from which all our knowledge of our duty must be 

By moral reasoning, I understand all reasoning 
that is brought to prove that such conduct is right, 
and deserving of moral approbation ; or that it is 
wrong ; or that it is indifferent, and, in itself, 
neither morally good nor ill. 

I think, all we can properly call moral judgments, 
are reducible to one or other of these, as all human 
actions, considered in a moral view, are either good, 
or bad, or indifferent. 

I know the term moral reasoning is often used by 
good writers in a more extensive sense ; but, as the 
reasoning I now speak of is of a peculiar kind, 
distinct from all others, and, therefore, ought to 
have a distinct name, I take the liberty to limit the 
name of moral reasoning to this kind. 

Let it be understood, therefore, that in the reason- 
ing I call moral, the conclusion always is. That some- 
thing in the conduct of moral agents is good or bad, 
in a greater or a less degree, or indifferent. 

All reasoning must be grounded on first principles. 
This holds in moral reasoning, as in all other kinds. 
There must, therefore, be in morals, as in all other 
sciences, first or self-evident principles, on which 


all moral reasoning is grounded, and on which 
it ultimately rests. From such self-evident prin- 
ciples, conclusions may be drawn synthetically with 
regard to the moral conduct of life ; and particular 
duties or virtues may be traced back to such prin- 
ciples, analytically. But, without such principles, 
we can no more establish any conclusion in morals, 
than we can build a castle in the air, without any 

§ 5. Observations concerning Conscience 

I shall now conclude this essay with some observa- 
tions concerning this power of the mind which we 
call Conscience, by which its nature may be better 

The first is, That, like all our other powers, it 
comes to maturity by insensible degrees, and may 
be much aided in its strength and vigour by proper 

A second observation is, That Conscience is 
peculiar to man. We see not a vestige of it in 
brute animals. It is one of those prerogatives by 
which we are raised above them. 

The next observation is — That Conscience is 
evidently intended by nature to be the immediate 
guide and director of our conduct, after we arrive at 
the years of understanding. 

It judges of every action before it is done. For 
1 Ibid., pp. 586-590. 

REID 183 

we can rarely act so precipitately but we have the 
consciousness that what we are about to do is 
right, or wrong, or indifferent. Like the bodily 
eye, it naturally looks forward, though its attention 
may be turned back to the past. 

To conceive, as some seem to have done, that its 
office is only to reflect on past actions, and to 
approve or disapprove, is, as if a man should con- 
ceive that the office of his eyes is only to look back 
upon the road he has travelled, and to see whether 
it be clean or dirty ; a mistake which no man can 
make who has made the proper use of his eyes. 

Conscience prescribes measures to every appetite, 
affection, and passion, and says to every other 
principle of action — So far thou mayest go, but no 

We may indeed transgress its dictates, but we 
cannot transgress them with innocence, nor even 
with impunity. 

We condemn ourselves, or, in the language of 
scripture, our heart condemns us, whenever we go 
beyond the rules of right and wrong which con- 
science prescribes. 

Other principles of action may liave more 
strength, but this only has authority. Its sentence 
makes us guilty to ourselves, and guilty in the eyes 
of our Maker, whatever other principle may be set 
in opposition to it. 

It is evident, therefore, that this principle has. 


from its nature, an authority to direct and determine 
with regard to our conduct ; to judge, to acquit, or to 
condemn, and even to publish ; an authority which 
belongs to no other principle of the human mind. 

It is the candle of the Lord set up within us, to 
guide our steps. Other principles may urge and 
impel, but this only authorizes. Other principles 
ought to be controlled by this ; this may be, but 
never ought to be controlled by any other, and 
never can be with innocence. 

The authority of conscience over the other active 
principles of the mind, I do not consider as a point 
that requires proof by argument, but as self-evident. 
For it implies no more than this — That in all cases 
a man ought to do his duty. He only who does in all 
cases what he ought to do, is the perfect man. 

The last observation is — That the Moral Faculty 
or Conscience is both an Active and an Intellectual 
power of the mind. 

It is an active power, as every truly virtuous 
action must be more or less influenced by it. Other 
principles may concur with it, and lead the same 
way ; but no action can be called morally good, in 
which a regard to what is right has not some in- 
fluence. Thus, a man who has no regard to justice, 
may pay his just debt, from no other motive but 
that he may not be thrown into prison. In this 
action there is no virtue at all. 

The moral principle, in particular cases, may be 

REID 185 

opposed by any of our animal principles. Passion 
or appetite may urge to what we know to be wrong. 
In every instance of this kind, the moral principle 
ought to prevail, and the more difficult its conquest 
is, it is the more glorious. 

In some cases, a regard to what is right may be 
the sole motive, without the concurrence or opposi- 
tion of any other principle of action ; as when a 
judge or an arbiter determines a plea between two 
different persons, solely from a regard to justice. 

Thus we see that conscience, as an active prin- 
ciple, sometime concurs with other active principles, 
sometimes opposes them, and sometimes is the sole 
principle of action. 

I conclude with observing, That conscience, or 
the moral faculty, is likewise an intellectual power. 

By it solely we have the original conceptions or 
ideas of right and wrong in human conduct. And 
of right and wrong there are not only many different 
degrees, by many different species. Justice and 
injustice, gratitude and ingratitude, benevolence 
and malice, prudence and folly, magnanimity and 
meanness, decency and indecency, are various 
moral forms, all comprehended under the general 
notion of right and wrong in conduct, all of them 
objects of moral approbation or disapprobation, 
in a greater or a less degree. 

The conception of these, as moral qualities, we 
have by our moral faculty ; and by the same 


faculty, when we compare them together, we per- 
ceive various moral relations among them. Thus, 
we perceive that justice is entitled to a small 
degree of praise, but injustice to a high degree of 
blame ; and the same may be said of gratitude and 
its contrary. When justice and gratitude interfere, 
gratitude must give place to justice, and unmerited 
beneficence must give place to both. 

Many such relations between the various moral 
qualities compared together, are immediately dis- 
cerned by our moral faculty. A man needs only 
to consult his own heart to be convinced of them. 

All our reasonings in morals, in natural jurispru- 
dence, in the law of nations, as well as our reasonings 
about the duties of natural religion, and about the 
moral government of the Deity, must be grounded 
upon the dictates of our moral faculty, as first 

As this faculty , therefore, furnishes the human mind 
with many of its original conceptions or ideas, as well 
as with the first principles of many important branches 
of human knowledge, it may justly be accounted an 
intellectual as well as an active power of the mind.^ 

§ 6. That Moral Approbation implies a 
Real Judgment 

The approbation of good actions, and disappro- 
bation of bad, are so familiar to every man come to 
1 Ibid., pp. 594-599. 

REID 187 

years of understanding, that it seems strange there 
should be any dispute about their nature. 

Whether we reflect upon our own conduct, or 
attend to the conduct of others with whom we live, 
or of whom we hear or read, we cannot help approv- 
ing of some things, disapproving of others, and re- 
garding many with perfect indifference. 

These operations of our minds we are conscious 
of every day and almost every hour we live. Men 
of ripe understanding are capable of reflecting upon 
them, and of attending to what passes in their own 
thoughts on such occasions ; yet, for half a century, 
it has been a serious dispute among philosophers 
what this approbation and disapprobation is, 
Whether there be a real judgment included in it, 
which, like all other judgments, must be true or 
false ; or. Whether it include no more but some 
agreeable or uneasy feeling, in the person who 
approves or disapproves. 

Mr Hume observes very justly, that this is a 
controversy started of late. Before the modern 
system of Ideas and Impressions was introduced, 
nothing would have appeared more absurd than to 
say, that when I condemn a man for what he has 
done, I pass no judgment at all about the man, but 
only express some uneasy feeling in myself. 

Nor did the new system produce this discovery 
at once, but gradually, by several steps, according 
as its consequences were more accurately traced. 


and its spirit more thoroughly imbibed by suc- 
cessive philosophers. 

Des Cartes and Mr Locke went no farther than 
to maintain that the Secondary Qualities of body — 
Heat and Cold, Sound, Colour, Taste, and Smell — 
which we perceive and judge to be in the external 
object, are mere feelings or sensations in our minds, 
there being nothing in bodies themselves to which 
these names can be applied ; and that the office 
of the external senses is not to judge of external 
things, but only to give us ideas of sensations, from 
which we are by reasoning to deduce the existence 
of a material world without us, as well as we can. 

Arthur Collier and Bishop Berkeley discovered, 
from the same principles, that the Primary, as well 
as the Secondary, Qualities of bodies, such as 
Extension, Figure, Solidity, Motion, are only 
sensations in our minds ; and, therefore, that there 
is no material world without us at all. 

The same philosophy, when it cam'e to be applied 
to matters of taste, discovered that beauty and 
deformity are not anything in the objects, to which 
men, from the beginning of the world, ascribed them, 
but certain feelings in the mind of the spectator. 

The next step was an easy consequence from all 
the preceding, that Moral Approbation and Dis- 
approbation are not Judgments, which must be 
true or false, but barely agreeable and uneasy 
Feelings or Sensations. 

REID 189 

Mr Hume made the last step in this progress, 
and crowned the system by what he calls his 
hypothesis — to wit, That Belief is more properly an 
act of the Sensitive than of the Cogitative part of 
our nature. 

Beyond this I think no man can go in this track ; 
sensation or feeling is all, and what is left to the 
cogitative part of our nature, I am not able to 

I have had occasion to consider each of these 
paradoxes, excepting that which relates to morals, 
in " Essays on the Intellectual Powers of Man " ; 
and, though they be strictly connected with each 
other, and with the system which has produced them, 
I have attempted to shew that they are inconsistent 
with just notions of our intellectual powers, no less 
than they are with the common sense and common 
language of mankind. And this, I think, will like- 
wise appear with regard to the conclusion relating 
to morals — to wit. That moral approbation is only 
an agreeable feeling, and not a real judgment. 

To prevent ambiguity as much as possible, let us 
attend to the meaning of Feeling and of Judgment. 
These operations of the mind, perhaps, cannot be 
logically defined ; but they are well understood, 
and easily distinguished, by their properties and 

A feeling must be agreeable, or uneasy, or 
indifferent. It may be weak or strong. It is 


expressed in language either by a single word, or 
by such a contexture of words as may be the 
subject or predicate of a proposition, but such as 
cannot by themselves make a proposition. For it 
implies neither affirmation nor negation ; and there- 
fore cannot have the qualities of true or false, which dis- 
tinguish propositions from all other forms of speech, 
and judgments from all other acts of the mind. 

That I have such a feeling, is indeed an affirmative 
proposition, and expresses testimony grounded 
upon an intuitive judgment. But the feeling is 
only one term of this proposition ; and it can only 
make a proposition when joined with another 
term, by a verb affirming or denying. 

As feeling distinguishes the animal nature from 
the inanimate ; so judging seems to distinguish the 
rational nature from the merely animal. 

Though judgment in general is expressed by one 
word in language, as the most complex operations 
of the mind may be ; yet a particular judgment 
can only be expressed by a sentence, and by that 
kind of sentence which logicians call a proposition, 
in which there must necessarily be a verb in the 
indicative mood, either expressed or understood. 

Every judgment must necessarily be true or 
false, and the same may be said of the proposition 
which expresses it. It is a determination of the 
understanding, with regard to what is true, or false, 
or dubious. ^ 

REID 191 

In judgment, we can distinguish the object about 
which we judge, from the act of the mind in judging 
of that object. In mere feeling there is no such 
distinction. The object of judgment must be 
expressed by a proposition ; and behef , disbehef , or 
doubt, always accompanies the judgment we form. 
If we judge the proposition to be true, we must 
believe it ; if we judge it to be false, we must dis- 
believe it ; and if we be uncertain whether it be 
true or false, we must doubt. 

These two operations of mind, when we consider 
them separately, are very different, and easily 
distinguished. When we feel without judging, or 
judge without feeling, it is impossible, without very 
gross inattention, to mistake the one for the other. 

But in many operations of the mind, both are 
inseparably conjoined under one name ; and when 
we are not aware that the operation is complex, 
we may take one ingredient to be the whole, and 
overlook the other. 

But in most of the operations of mind in which 
judgment or belief is combined with feeling, the 
feeling is the consequence of the judgment, and is 
regulated by it. 

Let me now consider how I am affected when I 
see a man exerting himself nobly in a good cause. 
I am conscious that the effect of his conduct on my 
mind is complex, though it may be called by one 
name. I look up to his virtue, I approve, I admire 


it. In doing so, I have pleasure indeed, or an 
agreeable feeling ; this is granted. But I find 
myself interested in his success and in his fame. 
This is affection ; it is love and esteem, which is 
more than mere feeling. The man is the object 
of this esteem ; but in mere feeling there is no 

I am likewise conscious that this agreeable 
feeling in me, and this esteem of him, depend 
entirely upon the judgment I form of his conduct. 
I judge that this conduct merits esteem ; and, 
while I thus judge, I cannot but esteem him, and 
contemplate his conduct with pleasure. Persuade 
me that he was bribed, or that he acted from some 
mercenary or bad motive, immediately my esteem 
and my agreeable feeling vanish. 

In the approbation of a good action, therefore, 
there is feeling indeed, but there is also esteem of the 
agent ; and both the feeling and the esteem depend 
upon the judgment we form of his conduct. 

When I exercise my moral faculty about my own 
actions or those of other men, I am conscious that 
I judge as well as feel. I accuse and excuse, I 
acquit and condemn, I assent and dissent, I believe 
and disbelieve, and doubt. These are acts of 
judgment, and not feelings. 

Suppose that, in a case well known to both, my 
friend says — Such a man did well and worthily, his 
conduct is highly approvable. This speech, according 

REID 193 

to all rules of interpretation, expresses my friend's 
judgment of the man's conduct. This judgment 
may be true or false, and I may agree in opinion 
with him, or I may dissent from him without offence, 
as we may differ in other matters of judgment. 

Suppose, again, that, in relation to the same case, 
my friend says — The mans conduct gave me a very 
agreeable feeling. 

This speech, if approbation be nothing but an 
agreeable feeling, must have the very same meaning 
with the first, and express neither more nor less. 
But this cannot be, for two reasons. 

First, Because there is no rule in grammar or 
rhetoric, nor any usage in language, by which 
these two speeches can be construed so as to have 
the same meaning. The first expresses plainly 
an opinion or judgment of the conduct of the man, 
but says nothing of the speaker. The second only 
testifies a fact concerning the speaker — to wit, that 
he had such a feeling. 

Another reason why these two speeches cannot 
mean the same thing is, that the first may be 
contradicted without any ground of offence, such 
contradiction being only a difference of opinion, 
which, to a reasonable man, gives no offence. But 
the second speech cannot be contradicted without 
an affront : for, as every man must know his own 
feelings, to deny that a man had a feeling which he 
affirms he had, is to charge him with falsehood. 



If moral approbation be a real judgment, which 
produces an agreeable feeling in the mind of him 
who judges, both speeches are perfectly intelligible, 
in the most obvious and literal sense. Their mean- 
ing is different, but they are related, so that the 
one may be inferred from the other, as we infer the 
effect from the cause, or the cause from the effect. 
I know, that what a man judges to be a very 
worthy action, he contemplates with pleasure ; and 
what he contemplates with pleasure must, in his 
judgment, have worth. But the judgment and the 
feeling are different acts of his mind, though con- 
nected as cause and effect. He can express either 
the one or the other with perfect propriety ; but 
the speech, which expresses his feeling, is altogether 
improper and inept to express his judgment, for 
this evident reason, that judgment and feeling, 
though in some cases connected, are things in their 
nature different.^ 

^ Ibid., pp. 670-673. 




There is in nature a well-known distinction of 
things progressive, and stationary, to which we 
must attend in the farther pursuit of our subject. 

To be stationary, it is not necessary that a subject 
should be incapable of change, even from the 
action of any external cause ; it is sufficient that 
it have not any principle of change in its own 
nature. To be progressive, on the contrary; does 
not consist in any variation or change which an 
external cause may produce ; but in those transi- 
tions, from one state to another, which proceed 
from a principle of advancement in the subject 

A block of stone, from the quarry, may receive, 
in the hands of a workman, any variety of forms, 
but left to itself, would remain in its state. 

A seedling plant on the contrary, in a favourable 
soil and exposure, takes root and grows of itself. 

Progressive natures are subject to vicissitudes of 
advancement or decline, but are not stationary, 
perhaps, in any period of their existence. Thus, in 



the material world, subjects organized being pro- 
gressive, when they cease to advance, begin to 
decline, however insensibly, at the time of their 
transition from one to the other. In this consist 
the operation or failure of vegetable and animal 
life. In their advancement, the matter of which 
they are composed accumulates, and at every 
period acquires a form that approaches to the end 
of their progress. The principle of life itself gains 
strength or ability to discharge, and to vary, the 
functions of nature. In their decline they fade, 
shrink, and abate of their vigour and force. 

Intelligence appears to be, in a still higher degree, 
a principle of progression, and subject to greater 
extremes of comparative advancement or degrada- 
tion. It is advanced by continual accessions of 
observation and knowledge ; of skill and habit, in 
the practice of arts ; of improving discernment 
of good and evil ; of resolute purpose or power. 
It declines through defect of memory, discernment, 
affection, and resolution. 

While subjects stationary are described by the 
enumeration of co-existent parts, and quiescent 
qualities, subjects progressive are characterized 
by the enumeration of steps, in the passage from 
one form or state of existence to another, and by 
the termination or point of approach, whether near 
or remote, to which the successive movements of 
their nature are directed. 


The rank of a progressive subject is to be esti- 
mated, not by its condition at any particular stage 
of its progress, but by its capacity and destination 
to advance in the scale of being. From the feeblest 
shoot or seed-leaf of the oak, though more diminu- 
tive than many plants of the garden, we already 
forecast the stately fabric it is designed to raise in 
the forest. In the human infant, though inferior 
to the young of many other animals, we anticipate 
the beauty of youth, the vigorous soul of manhood, 
and the wisdom of age. And the highest rank, 
in the scale of created existence, is due to that 
nature, if such there be, which is destined to grow 
in perfection, and may grow without end : its good 
is advancement, and its evil, decline. 

We are inclined to consider progression as made 
up of stationary periods ; as we consider a circle 
as a polygon of an infinite number of sides ; a 
fluid as made up of solid parts indefinitely small ; 
and duration itself, as made up of successive 
points, or indivisible moments of time. 

In this our conception is inaccurate, and our 
reasoning, of course, likely to become incorrect. 
Progression may, no doubt, be divided into periods ; 
but in no period, perhaps, is the subject stationary. 
Every subdivision, like the whole of its progress, is 
a transition from one state to another, and through 
states intermediate, more or less numerous according 
to the divisions under which we are pleased to 


conceive them. The progress of intelligent being, 
for instance, may be more or less rapid, but is 
continual ; and in the very continuance of exist- 
ence, and the repetition of consciousness and 
perception, must receive continual increments of 
knowledge and thought. Or in the failure of the 
source from which it derives improvement, it is 
likely to incur degradation and decline. 

For our purpose, however, it is sufficient to 
observe, that the state of nature or the distinctive 
character of any progressive being is to be taken, not 
from its description at the outset, or at any subse- 
quent stage of its progress ; but from an accumula- 
tive view of its movement throughout. The oak 
is distinguishable from the pine, not merely by its 
seed leaf ; but by every successive aspect of its 
form ; by its foliage in every successive season ; by 
its acorn ; by its spreading top ; by its lofty growth, 
and the length of its period. And the state of 
nature, relative to every tree in the wood, includes 
all the varieties of form or dimension through which 
it is known to pass in the course of its nature. 

By parity of reason, the natural state of a living 
creature includes all its known variations, from the 
embryo and the foetus to the breathing animal, the 
adolescent and the adult, through which life in all 
its varieties is known to pass. 

The state of nature, relative to man, is also a 
state of progression equally real, and of greater 


extent. The individual receives the hrst stamina 
of his frame in a growing state. His stature is 
waxing, his Hmbs and his organs gain strength, and 
he himself a growing facility in the use of them. 
His faculties improve by exercise, and are in a 
continual state of exertion. 

If his thoughts pass from one subject to another, 
he can return to the subject he has left, with some 
acquired advantage of discernment or compre- 
hension. He accumulates perceptions and observa- 
tions, takes cognizance of new subjects, without 
forgetting the old ; knows more, of course, at every 
subsequent period than he did in a former ; reasons 
more securely ; penetrates obscurities, which at first 
embarrassed him ; and performs every operation of 
thought with more facility and more success. 

With respect to the period of his existence he 
sees it but in part. When he looks back to the point 
from which he set out, he cannot descry it ; when 
he looks forward to the end of his line, he cannot 
foresee it. He may observe the birth and the death 
of a fellow creature, but knows nothing of his own. 
If he were to assume the earliest date he remembers 
as the beginning of his existence, he might soon 
be convinced that he overlooked a considerable 
period which had preceded ; or if he should suppose 
his being to end with the dissolution of his animal 
frame, it is possible he might be equally mistaken. 
Yet he finds nothing in the world around him 


beyond the limits of what he can collect from the 
remembrance of the past, or infer by sagacity from 
the laws of nature in foresight of the future, from 
which he can fix any certain marks of his own 
beginning or his end. 

Such, without entering into the peculiarities or 
unequal degrees of power incident to different men, 
we may assume as the state of nature relative to 
the individual. 

The state of nature relative to the species is 
differently constituted, and of different extent. It 
consists in the continual succession of one genera- 
tion to another ; in progressive attainments made 
by different ages ; communicated with additions 
from age to age ; and in periods, the farthest 
advanced, not appearing to have arrived at any 
necessary limit. This progress indeed is subject 
to interruption, and may come to a close, or give 
way to vicissitude at any of its stages ; but not more 
necessarily at the period of highest attainment than 
at any other. 

So long as the son continues to be taught what 
the father knew, or the pupil begins where the tutor 
has ended, and is equally bent on advancement ; to 
every generation the state of arts and accommoda- 
tions already in use serves but as groundwork for new 
invention and successive improvement. As Newton 
did not acquiesce in what was observed by Kepler 
and Galileo ; no more have successive astrono- 


mers restricted their view to what Newton has 
demonstrated. And, with respect to the mechanic 
and commercial arts, even in the midst of the most 
laboured accommodations, so long as there is any 
room for* improvement, invention is busy as if 
nothing had yet been done to supply the necessities, 
or complete the conveniences of human life. But 
even here, and in all its steps of progression, this 
active nature, in respect to the advantages, whether 
of knowledge or art, derived from others, if there 
be not a certain effort to advance, is exposed to 
reverse and decline. The generation, in which there 
is no desire to know more or practise better than its 
predecessors, will probably neither know so much nor 
practise so well. And the decline of successive gener- 
ations, under this wane of intellectual ability, is not 
less certain than the progress made under the opera- 
tion of a more active and forward disposition. 

Such is the state of nature relative to the human 
species ; and, in this, as in every other progressive 
subject, the present being intermediate to the past 
and the future, may be different from either. Each 
is a part of the whole ; and neither can, with any 
reason, be said to be more natural than the others. 
It cannot be said, that it is more natural for the 
oak to spring from its seed than to overshadow the 
plain ; that it is more natural for water to gush 
from the land in springs than to flow in rivers, and 
to mix with the sea. 


The state of nature relative to man, however, is 
sometimes a mere term of abstraction, in which 
he is stated apart from the society he forms, from 
the art he invents, the science he acquires, or 
the poHtical estabhshment he makes. And, when 
his progress in any of these respects is to be con- 
sidered, it is no doubt convenient to consider the 
particular in question apart from himself, and from 
every thing else. It is not, however, to be supposed, 
that man ever existed apart from the qualities and 
operations of his own nature, or that any one 
operation and quality existed without the others. 
The whole, indeed, is connected together, and any 
part may vary in measure or degree, while in its 
nature and kind it is still the same. 

The child may be considered apart from his parent, 
and the parent apart from his child ; but the latter 
would not have existed without the former. If we 
trace human society back to this its simplest 
constitution, even there the society was real. 
If we trace human thought back to its simplest 
exertions, even there it was an exercise of under- 
standing, and some effort of invention or skill. 

The groups in which the rudest of men were 
placed, had their chiefs and their members ; and 
nothing that the human species ever attained, in 
the latest period of its progress, was altogether with- 
out a germ or principle from which it is derived, in 
the earliest or most ancient state of mankind. 


It may no doubt be convenient, we may again 
repeat, in speculation, or in assigning the origin 
and in deriving the progress of any attainment, to 
consider the attainment itself abstractly, or apart 
from the faculty or power by which it is made ; 
and we must not deny ourselves the use of such 
abstractions, in treating of human nature, any more 
than in treating of any other subject. But there 
is a caution to be observed in the use of abstrac- 
tions, relating to any subject whatever : That 
they be not mistaken for realities, nor obtruded for 
historical facts. 

The language of geometry is necessarily abstract. 
A point is mere place, considered apart from any 
dimension whatever. A line is length, considered 
apart from breadth or thickness. A surface 
is length and breadth, considered apart from thick- 
ness. And, in a solid, all the dimensions of length, 
breadth, and thickness, are admitted. But the 
geometrical abstractions are nowhere mistaken 
for realities : length is not supposed to exist 
without breadth, nor length and breadth without 
thickness. Or, if such mistakes are actually 
made, yet, no one would infer that lines are more 
natural than surfaces, or surfaces more natural 
than solids. 

Such mistake and misapprehension of terms is 
scarcely admitted, except in treating of human 
nature. In every other progressive subject, pro- 


gression itself, not any particular step in the pro- 
gress, is supposed to constitute the natural state. 
The last shoot of the oak, after it has stood five hun- 
dred years in the forest, and carried a thousand 
branches, is not deemed less natural than the first. 

Under this term, of the State of Nature, authors 
affect to look back to the first ages of man, not with- 
out some apparent design to depreciate his nature, 
by placing his origin in some unfavourable point of 
view ; as we derogate, from the supposed honours 
of a family, by looking back to the mechanics or 
peasants, from whom its ancestors were descended. 

Hobbes contended, that men were originally 
in a state of war, and undisposed to amity or peace ; 
that society, altogether unnatural to its members, 
is to be established and preserved by force. Or 
this, at least, may be supposed to follow from his 
general assumption that the state of nature was a 
state of war. 

If this point must be seriously argued, we may ask 
in what sense war is the state of nature ? Not 
surely the only state of which men are susceptible ; 
for we find them at peace as well as at war : nor 
can we suppose it the state which mankind ought at 
all times to prefer ; for it labours under many 
inconveniences and defects. But it was, we may be 
told, the first and the earliest state, from which 
men were relieved by convention and adventitious 


This assertion, that war was the earhest state of 
mankind, is made without proof ; for the first 
ages of the human species, in times past, are as 
Httle known as the last, that may close the scene 
of its being in times to come. In every progression, 
it is true, may be conceived a point of origin, and 
a point of termination, to be collected from the 
direction in which the progress proceeds. The sun, 
even by a person who never saw him rise or set, 
may be supposed, from the course he holds, to have 
risen in the east, and to set in the west. Man, who 
is advancing in knowledge and art, may be supposed 
to have begun in ignorance or rudeness ; but it is 
not necessary to suppose that a species, of whom 
the individuals are sometimes at war, and some- 
times at peace, must have begun in war. There is, 
on the contrary, much reason to suppose, that they 
began in peace, and continued in peace, until 
some occasion of quarrel arose between them. 

The progress of the species, in population and 
numbers, implies an original peace, at least, between 
the sexes, and between the parent and his child, 
in family together ; and, if we are to suppose a 
state of war between brothers, this, at least, must 
have been posterior to the peace in which they were 
born and brought up, to the peace in which they 
arrived at the possession of those talents, and that 
force, which they come to employ for mutual 


Another philosopher, in this school of nature, has 
chosen to fix the original description of man, in a 
state of brutaHty, unconscious of himself, and 
ignorant of his kind ; so far from being destined 
to the use of reason, that all the attempts he has 
made at the exercise of this dangerous faculty have 
opened but one continual source of depravation 
and misery. 

But, as the former of these philosophers has not 
told us what beneficent power, different from man 
himself, has made peace for this refractory being ; 
no more has the other informed us, who invented 
reason for man ; whose thoughts and reflections 
first disturbed the tranquillity of his brutal nature, 
and brought this victim of care into this anxious 
state of reflection, to which are imputed so many 
of his follies and sufferings. 

Until we are told by whom the state of nature 
was done away, and a new one substituted, we must 
continue to suppose that this is the work of man 
himself ; and the whole of what these shrewd 
philosophers have taught, amounts to no more than 
this, that man would be found in a state of war, or 
in a state of brutality, if it were not for himself, for 
his own qualifications and his endeavours to obtain 
a better ; and that, in reality, the situation he gains 
is the effect of a faculty by which he is disposed 
to choose for himself. 

This we are ready to admit. Man is made for 


society and the attainments of reason. If, by any 
conjuncture, he is deprived of these advantages, 
he will sooner or later find his way to them. If he 
came from a beginning, defective in these respects, 
he was, from the first, disposed to supply his 
defects ; in process of time has actually done so ; 
continued to improve upon every advantage he 
gains ; and thus to advance, we may again repeat, 
is the state of nature relative to him. 

It were absurd to think of depreciating a pro- 
gressive being, by pointing out the state of defect, 
from which he has passed, to the attainment of a 
better and a higher condition ; for so to pass is 
the specific excellence of his nature. 

The grandeur of the forest is not the less real, for 
its having sprung up from among the weeds of the 
field : the genius of Newton not the less to be 
admired, for his having grown up from the ignorance 
and simplicity of his infant years : nor the policy 
of Athens, Sparta, or Rome, less to be valued, 
because they may have sprung from hordes, no 
way superior to those who are now found in 
different parts of Africa or America. 

It is the nature of progression to have an origin, 
far short of the attainments which it is directed to 
make ; and not any precise measure of attainment, 
but the passage or transition from defect to per- 
fection is that which constitutes the felicity of a 
progressive nature. The happy being, accordingly, 



whose destination is to better himself, must not 
consider the defect under which he labours, at the 
outset, or in any subsequent part of his progress, 
as a limit set to his ambition, but as an occasion 
and a spur to his efforts. 

The life and activity of intelligent beings con- 
sists in the consciousness or perception of an im- 
proveable state, and in the effort to operate upon 
it for the better. This constitutes an unremitting 
principle of ambition in human nature. Men have 
different objects, and succeed unequally in the pur- 
suit of them : but every person, in one sense or 
another, is earnest to better himself. 

Man is by nature an artist, endowed with in- 
genuity, discernment, and will. These faculties 
he is qualified to employ on different materials ; 
but is chiefly concerned to employ them on him- 
self: over this subject his power is most im- 
mediate and most complete ; as he may know 
the law, according to which his progress is effected, 
by conforming himself to it, he may hasten or 
secure the result. 

The bulk of mankind are, like other parts of the 
system, subjected to the law of their nature, and, 
without knowing it, are led to accomplish its pur- 
pose : while they intend no more than subsistence 
and accommodation or the peace of society, and the 
safety of their persons and their property, their 
faculties are brought into use, and they profit by 


exercise. In mutually conducting their relative 
interests and concerns, they acquire the habits 
of political life ; are made to taste of their highest 
enjoyments, in the affections of benevolence, 
integrity, and elevation of mind; and, before 
they have deliberately considered in what the 
merit or felicity of their own nature consist, 
have already learned to perform many of its 
noblest functions. 

Nature in this as in many other instances does 
not entrust the conduct of her works to the pre- 
carious views and designs of any subordinate agent. 
But if the progress of man in every instance were 
matter of necessity or even of contingency, and no 
way dependent on his will, nor subjected to his 
command, we should conclude that this sovereign 
rank and responsibility of a moral agent with which 
he is vested were given in vain ; and the capacity 
of erecting a fabric of art, on the foundation of 
the laws of nature, were denied to him in that 
department precisely in which they are of the highest 
account. If he may work on the clay that is placed 
under his foot, and form it into models of grace and 
beauty ; if he may employ the powers of gravita- 
tion, elasticity, and magnetism, as the ministers 
of his pleasure ; we may suppose, also, that the 
knowledge of laws operating on himself should 
direct him how to proceed, and enable him to 
hasten the advantages, to which his progressive 


nature is competent. If his Maker have destined 
his faculties to improve by exercise, and by the 
attainment of habits, there is no doubt that he 
himself may choose what exercise he will perform, 
and what habits he shall acquire. 

But in order to profit by the laws of progression 
which take place in his frame, it behoves him to 
recollect what they are, and to take his resolution 
respecting the purpose to which he will apply their 

To this object, he is urged at once by the double 
consideration of a good to be obtained, and of an 
evil to be avoided. Most subjects in nature, 
which, from the energy of a salutary principle, are 
susceptible of advancement, are likewise, by the 
failure or abuse of that principle, susceptible of 
degradation and ruin. Plants and animals are 
known to perish, in the same gradual manner in 
which they advance into strength and beauty. 
Man, with whom the sources of good and of evil 
are more entrusted to his own management, is 
likewise exposed, in a much higher degree, to the 
extremes of comparative degradation and misery. 
The progress of nations in one age to high measures 
of intellectual attainment and cultivated manners 
is not more remarkable than the decline that some- 
times ensues in their fall to extreme depravation 
and intellectual debility. 

It may not be in the power of the individual 


greatly to promote the advancement or to retard 
the dedine of his country. But every person, 
being principally interested in himself, is the 
absolute master of his own will, and for the choice 
he shall have made is alone responsible.^ 

^ Principles of Moral and Political Science, vol. i. pp. 189-202. 




On hearing these propositions, — I exist, things 
equal to one and the same thing are equal to one 
another, the sun rose to-day, there is a God, in- 
gratitude ought to be blamed and punished, the 
three angles of a triangle are equal to two right 
angles, etc. — I am conscious that my mind admits 
and acquiesces in them. I say, that I believe them 
to be true ; that is, I conceive them to express 
something conformable to the nature of things. 
Of the contrary propositions I should say, that my 
mind does not acquiesce in them, but disbelieves 
them, and conceives them to express something 
not conformable to the nature of things. My 
judgment in this case, I conceive to be the same 
that I should form in regard to these propositions, 
if I were perfectly acquainted with all nature, in all 
its parts, and in all its laws. 

If I be asked, what I mean by the nature of things, 
I cannot otherwise explain myself than by saying, 
that there is in my mind something which induces 



me to think, that every thing existing in nature is 
determined to exist, and to exist after a certain 
manner, in consequence of established laws ; and 
that whatever is agreeable to those laws is agree- 
able to the nature of things, because by those laws 
the nature of all things is determined. Of those 
laws I do not pretend to know any thing except so 
far as they seem to be intimated to me by my own 
feelings, and by the suggestions of my own under- 
standing. But these feelings and suggestions are 
such, and affect me in such a manner, that I cannot 
help receiving them, and trusting in them, and 
believing that their intimations are not fallacious, 
but such as I should approve if I were perfectly 
acquainted with every thing in the universe, and 
such as I may approve, and admit of, and regulate 
my conduct by, without danger of any incon- 

It is not easy on this subject to avoid identical 
expressions. I am not certain that I have been able 
to avoid them. And perhaps I might have ex- 
pressed my meaning more shortly and more clearly, 
by saying, that I account that to be truth which the 
constitution of our nature determines us to believe, 
and that to be falsehood which the constitution of 
our nature determines us to disbelieve. Believing 
and disbelieving are simple acts of the mind ; I can 
neither define nor describe them in words ; and 
therefore the reader must judge of their nature 

BE ATT IE 219 

from his own experience. We often believe what 
we afterwards find to be false ; but while belief 
continues, we think it true ; when we discover its 
falsity, we believe it no longer. 

Hitherto I have used the word belief to denote an 
act of the mind which attends the perception of 
truth in general. But truths are of different kinds ; 
some are certain, others only probable : and we 
ought not to call that act of the mind which attends 
the perception of certainty, and that which attends 
the perception of probability, by one and the same 
name. Some have called the former conviction, 
and the latter assent. All convictions are equally 
strong ; but assent admits of innumerable degrees, 
from moral certainty, which is the highest degree, 
downward, through the several stages of opinion, to 
that suspense of judgment which is called doubt. 

We may, without absurdity, speak of probable 
truth, as well as of certain truth. Whatever a 
rational being is determined, by the constitution 
of his nature, to admit as probable, may be called 
probable truth ; the acknowledgment of it is as 
universal as that rational nature, and will be as 
permanent. But, in this enquiry, we propose to 
confine ourselves chiefly to that kind of truth which 
may be called certain, which enforces our con- 
viction, and the belief of which, in a sound mind, 
is not tinctured with any doubt or uncertainty. 

The investigation and perception of truth is 


commonly ascribed to our rational faculties ; and 
these have by some been reduced to two, — Reason 
and Judgment ; the former being supposed to be 
conversant about certain truths, the latter chiefly 
about probabilities. But certain truths are not all 
of the same kind ; some being supported by one 
sort of evidence and others by another : different 
energies of the understanding must therefore be 
exerted in perceiving them ; and these different 
energies must be expressed by different names, 
if we would speak of them distinctly and intelli- 
gibly. The certainty of some truths, for instance, 
is perceived intuitively ; the certainty of others is 
perceived not intuitively, but in consequence of a 
proof. Most of the propositions of Euclid are of 
the latter kind ; the axioms of geometry are of the 
former. Now, if that faculty by which we perceive 
truth in consequence of a proof, be called Reason, 
that power by which we perceive self-evident truth 
ought to be distinguished by a different name. 
It is of little consequence what name we make 
choice of, provided that in choosing it we depart not 
from the analogy of language ; and that, in applying 
it, we avoid equivocation and ambiguity. Some 
philosophers of note have given the name of 
Common Sense to that faculty by which we perceive 
self-evident truth ; and, as the term seems proper 
enough, we shall adopt it.^ 

1 Essay on the Nature and Immutability of Truth, pp. 22-27. 


The term Common Sense has several different 
significations. i. Sometimes it seems to be 
synonymous with prudence. Thus we say, that a 
man has a large stock of common sense, who is 
quick in perceiving remote consequences, and 
thence instantaneously determines concerning the 
propriety of present conduct. 2. We often meet 
with persons of great sagacity in most of the 
ordinary affairs of life, and very capable of accurate 
reasoning, who yet, without any bad intention, 
commit blunders in regard to decorum ; by saying 
or doing what is offensive to their company, and 
inconsistent with their own character ; and this 
we are apt to impute to a defect in common sense. 
But it seems rather to be owing to a defect in that 
kind of sensibility, or sympathy, by which we sup- 
pose ourselves in the situations of others, adopt 
their sentiments, and in a manner perceive their 
thoughts ; and which is indeed the foundation of 
good breeding. It is by this secret, and sudden, and 
(to those who are unacquainted with it) inexplicable 
communication of feelings, that a man is enabled 
to avoid what would appear incongruous or offensive. 
They who are prompted by inclination, or obliged 
by necessity, to study the art of recommending 
themselves to others, acquire a wonderful facility 
in perceiving and avoiding all possible ways of 
giving offence ; which is a proof, that this kind of 
sensibility may be improved by habit ; although 


there are, no doubt, in respect of this, as well as 
of some other modifications of perception, original 
and constitutional differences in the frame of 
different minds. 3. Some men are distinguished by 
an uncommon acuteness in discovering the char- 
acters of others ; they seem to read the soul in the 
countenance, and with a single glance to penetrate 
the deepest recesses of the heart. In their presence, 
the hypocrite is detected, notwithstanding his 
specious outside ; the gay effrontery of the cox- 
comb cannot conceal his insignificance ; and the 
man of merit appears conspicuous under all the dis- 
guises of an ungainly modesty. This talent is 
sometimes called Common Sense ; but improperly. 
It is far from being common ; it is even exceedingly 
rare : it is to be found in men who are not remark- 
able for any other mental excellence ; and we often 
see those who in other respects are judicious enough, 
quite destitute of it. 4. Neither ought every 
common opinion to be referred to common sense. 
Modes in dress, religion, and conversation, however 
absurd in themselves, may suit the notions or the 
taste of a particular people : but none of us will 
say, that it is agreeable to common sense, to worship 
more gods than one ; to believe that one and the 
same body may be in ten thousand different 
places at the same time ; to like a face the better 
because it is painted, or to dislike a person because 
he does not lisp in his pronunciation. Lastly, the 

BE ATT IE 223 

term Common Sense has been used by some philo- 
sophers to signify that power of the mind which 
perceives truth, or commands behef, not by pro- 
gressive argumentation, but by an instantaneous 
and instinctive impulse ; derived neither from 
education nor from habit, but from nature ; acting 
independently on our will, whenever its object is 
presented, according to an established law, and 
therefore not improperly called Sense ; and acting 
in a similar manner upon all mankind, and there- 
fore properly called Common Sense. It is in this 
signification that the term Common Sense is used 
in the present enquiry. 

That there is a real and essential difference 
between these two faculties ; that common sense 
cannot be accounted for, by being called the per- 
fection of reason, nor reason, by being resolved into 
common sense, will perhaps appear from the 
following remarks, i. We are conscious, from 
internal feeling, that the energy of understanding 
which perceives intuitive truth, is different from 
that other energy which unites a conclusion with 
a first principle, by a gradual chain of intermediate 
relations. We believe the truth of an investigated 
conclusion, because we can assign a reason for our 
belief ; we believe an intuitive principle, without 
being able to assign any other reason but this, that 
we know it to be true ; or that the law of our 
nature, or the constitution of the human under- 


standing, determines us to believe it. 2. We 
cannot discern any necessary connection between 
reason and common sense : they are indeed gener- 
ally connected ; but we can conceive a being 
endued with the one who is destitute of the other. 
Nay, we often find, that this is in fact the case. 
In dreams, we sometimes reason without common 
sense. Through a defect of common sense, we adopt 
absurd principles ; but supposing our principles 
true, our reasoning is often unexceptionable. ^ 

In the science of body, glorious discoveries have 
been made by a right use of reason. When men 
are once satisfied to take things as they find them ; 
when they believe Nature upon her bare declaration, 
without suspecting her of any design to impose 
upon them ; when their utmost ambition is to be 
her servants and interpreters ; then, and not till 
then, will philosophy prosper. But of those who 
have applied themselves to the science of human 
nature, it may truly be said, (of many of them at 
least), that too much reasoning hath made them 
mad. Nature speaks to us by our external, as well 
as by our internal, senses ; it is strange that we 
should believe her in the one case, and not in the 
other ; it is most strange, that supposing her 
fallacious, we should think ourselves capable of 
detecting the cheat. Common sense tells me, that 
the ground on which I stand is hard, material, and 
I Ibid.: pp. 31-35- 

BE ATT IE 225 

solid, and has a real, separate, independent 
existence. Berkeley and Hume tell me, that I am 
imposed upon in this matter ; for that the ground 
under my feet is really an idea in my mind ; that 
its very essence consists in being perceived ; and 
that the same instant it ceases to be perceived, it 
must also cease to exist ; in a word, that to he, and 
to he perceived, when predicated of the ground, the 
sun, the starry heavens, or any corporeal object, 
signify precisely the same thing. Now, if my 
common sense be mistaken, who shall ascertain 
and correct the mistake ? Our reason, it is said. 
Are then the inferences of reason in this instance 
clearer, and more decisive, than the dictates of 
common sense ? By no means : I still trust to my 
common sense as before ; and I feel that I must do 
so. But supposing the inferences of the one faculty 
as clear and decisive as the dictates of the other ; 
yet who will assure me, that my reason is less liable 
to mistake than my common sense ? And if reason 
be mistaken, what shall we say ? Is this mistake 
to be rectified by a second reasoning, as liable to 
mistake as the first ? — In a word, we must deny 
the distinction between truth and falsehood, adopt 
universal scepticism, and wander without end from 
one maze of uncertainty to another ; a state of 
mind so miserable, that Milton makes it one of the 
torments of the damned ; — or else we must suppose, 
that one of these faculties is of higher authority 



than the other ; and that either reason ought to 
submit to common sense, or common sense to 
reason, whenever a variance happens between 
them : — in other words, that no doctrine ought to 
be admitted as true that exceeds behef, and 
contradicts a first principle. 

It has been said, that every enquiry in philosophy 
ought to begin with doubt ; — that nothing is to be 
taken for granted, and nothing believed, without 
proof. If this be admitted, it must also be admitted, 
that reason is the ultimate judge of truth, to which 
common sense must continually act in subordina- 
tion. But this I cannot admit ; because I am able 
to prove the contrary by incontestable evidence. 
I am able to prove, that " except we beheve many 
things without proof, we never can believe any 
thing at all ; for that all sound reasoning must 
ultimately rest on the principles of common sense ; 
that is, on principles intuitively certain or in- 
tuitively probable ; and consequently, that common 
sense is the ultimate judge of truth, to which reason 
must continually act in subordination." — This I 
mean to prove by a fair induction of particulars.^ 
1 Ibid., pp. 38-40. 




I. All the different kinds of philosophical inquiry, 
and all that practical knowledge which guides our 
conduct in life, presuppose such an established 
order in the succession of events, as enables us to 
form conjectures concerning the future, from the 
observation of the past. 

2. In the phenomena of the material world, and 
in many of the phenomena of mind, more especially 
in those which depend on the instincts of the brutes, 
we expect, with the most perfect confidence, 
that in the same combinations of circumstances 
the same results will take place ; and it is owing to 
this expectation (justified by the experience of all 
ages) that the instincts of the brutes, as well as 
the laws of matter, become a source of power to 
man. In both cases, the established order of nature 
affords abundant evidence that it was chiefly with a 
view to our accommodation and happiness that the 
arrangements of this world were made. The laws 



which regulate the course of human affairs, are 
investigated with much greater difficulty : but, 
even in this class of events, such a degree of order 
may frequently be traced, as furnishes general rules 
of great practical utility ; and this order becomes 
the more apparent, in proportion as we generalize 
our observations. 

3. Our knowledge of the laws of nature is entirely 
the result of observation and experiment ; for there 
is no instance in which we perceive such a neces- 
sary connexion between two successive events, as 
might enable us to infer the one from the other by 
reasoning a priori. We find, from experience, 
that certain events are invariably conjoined, so that 
when we see the one, we expect the other ; but our 
knowledge in such cases extends no farther than 
the fact. 

4. To ascertain those established conjunctions 
of successive events, which constitute the order of 
the universe ; — to record the phenomena which it 
exhibits to our observation, and to refer them to 
their general laws, is the great business of philo- 
sophy. Lord Bacon was the first person who was 
fully aware of the importance of this fundamental 
truth. The ancients considered philosophy as the 
science of causes ; and hence were led to many 
speculations, to which the human faculties are 
altogether incompetent. 

5. The ultimate object of philosophical inquiry 


is the same which every man of plain understanding 
proposes to himself, when he remarks the events 
which fall under his observation, with a view to the 
future regulation of his conduct. The more know- 
ledge of this kind we acquire, the better can we 
accommodate our plans to the established order of 
things, and avail ourselves of natural Powers and 
Agents for accomplishing our purposes. 

6. The knowledge of the Philosopher differs from 
that sagacity which directs uneducated men in 
the business of life, not in kind, but in degree, and 
in the manner in which it is acquired. 1st, By 
artificial combinations of circumstances, or, in 
other words, by experiments, he discovers many 
natural conjunctions which would not have occurred 
spontaneously to his observation. 2dly, By 
investigating the general Laws of Nature, and by 
reasoning from them synthetically, he can often 
trace an established order, where a mere observer 
of facts would perceive nothing but irregularity. 
This last process of the mind is more peculiarly 
dignified with the name of Philosophy ; and the 
object of the rules of philosophizing is to explain 
in what manner it ought to be conducted. 

7. The knowledge which is acquired of the course 
of Nature by mere observation, is extremely limited, 
and extends only to cases in which the uniformity 
of the observed phenomena is apparent to our 
senses. This happens, either when one. single 


law of nature operates separately, or when different 
laws are always combined together in the same 
manner. In most instances, however, when differ- 
ent laws are combined, the result varies in every 
particular case, according to the different circum- 
stances of the combination ; and it is only by 
knowing what the laws are which are concerned in 
any expected phenomenon, and by considering in 
what manner they modify each other's effects, that 
the result can be predicted. 

8. Hence it follows, that the first step in the 
study of Philosophy is to ascertain the simple and 
general laws on which the complicated phenomena 
of the universe depend. Having obtained these 
laws, we may proceed safely to reason concerning 
the effect resulting from any given combination 
of them. In the former instance, we are said to 
carry on our inquiries in the way of Analysis ; in 
the latter in that of Synthesis. — [Scala Ascensoria 
et Descensoria. — Bacon.] 

9. To this method of philosophizing, (which is 
commonly distinguished by the title of the Method 
of Induction), we are indebted for the rapid progress 
which physical knowledge has made since the time 
of Lord Bacon. The publication of his writings 
fixes one of the most important eras in the history 
of science. Not that the reformation which has 
since taken place in the plan of philosophical 
inquiry is to be ascribed entirely to him ; for 


although he did more to forward it than any other 
individual, yet his genius and writings seem to have 
been powerfully influenced by the circumstances 
and character of the age in which he lived ; and 
there can be little doubt that he only accelerated 
an event which was already prepared by many 
concurrent causes.^ 


The effect of custom in connecting together 
different thoughts, in such a manner that the one 
seems spontaneously to follow the other, is one of 
the most obvious facts with respect to the opera- 
tions of the mind. To this law of our constitution, 
modern philosophers have given the name of the 
Association of Ideas. Of late, the phrase has been 
used in a more extensive sense, to denote the tend- 
ency which our thoughts have to succeed each 
other in a regular train ; whether the connexion 
between them be established by custom, or arise 
from some other associating principle. 

What the different circumstances are which 
regulate the succession of our thoughts, it is not 
possible, perhaps, to enumerate completely. The 
following are some of the most remarkable : Re- 
semblance, Analogy, Contrariety, Vicinity in Place, 
Vicinity in Time, Relation of Cause and Effect, 
Relation of Means and End, Relation of Premises 

1 " Outlines of Moral Philosophy," Works, vol. ii, pp. $-S. 


and Conclusion. Whether some of these may not 
be resolvable into others, is not very material to 
inquire. The most powerful of all the associating 
principles is undoubtedly Custom ; and it is that 
which leads to the most important inquiries of a 
practical nature. 

Among the associating principles already enumer- 
ated, there is an important distinction. The 
relations on which some of them are founded are 
obvious ; and connect our thoughts together, when 
the attention is not directed particularly to any 
subject. Other relations are discovered only in 
consequence of efforts of meditation or study. Of 
the former kind are the relations of Resemblance 
and Analogy, of Contrariety, of Vicinity in Time and 
Place ; of the latter, the Relations of Cause and 
Effect, of Means and End, of Premises and Con- 
clusion. It is owing to this distinction that 
transitions, which would be highly offensive in 
philosophical writing, are the most pleasing of 
any in poetry. 

In so far as the train of our thoughts is regulated 
by the laws of Association, it depends on causes 
of the nature of which we are ignorant, and over 
which we have no direct or immediate control. At 
the same time it is evident, that the will has some 
influence over this part of our constitution. To 
ascertain the extent and the limits of this influence, 
is a problem of equal curiosity and importance. 


We have not a power of summoning up any 
particular thought, till that thought first solicit 
our notice. Among a crowd, however, which 
present themselves, we can choose and reject. We 
can detail a particular thought, and thus check 
the train that would otherwise have taken place. 

The indirect influence of the will over the train 
of our thoughts is very extensive. It is exerted 
chiefly in two ways : — i. By an effort of attention, we 
can check the spontaneous course of our ideas, and 
give efficacy to those associating principles which 
prevail in a studious and collected mind. 2. By 
practice, we can strengthen a particular associating 
principle to so great a degree, as to acquire a 
command over a particular class of our ideas. 

The effect of habit, in subjecting to the will those 
intellectual processes, which are the foundation of 
wit, — of the mechanical part of poetry, (or, in other 
words, of the powers of versification and rhyming), — 
of poetical fancy, — of invention in the arts and 
sciences ; and, above all, its effect in forming a 
talent for extempore elocution, furnish striking 
illustrations of this last remark. 

Of all the different parts of our constitution, 
there is none more interesting to the student of 
Moral Philosophy than the laws which regulate 
the Association of Ideas. From the intimate and 
almost indissoluble combinations which we are thus 
led to form in infancy and in early youth, may be 


traced many of our speculative errors ; many of 
our most powerful principles of action ; many 
perversions of our moral judgment ; and many of 
those prejudices which mislead us in the conduct 
of life. By means of a judicious education, this 
susceptibility of the infant mind might be rendered 
subservient not only to moral improvement, but to 
the enlargement and multiplication of our capacities 
of enjoyment. 1 


By means of the Association of Ideas, a constant 
current of thoughts, if I may use the expression, is 
made to pass through the mind while we are awake. 
Sometimes the current is interrupted, and the 
thoughts diverted into a new channel, in conse- 
quence of the ideas suggested by other men, or of 
the objects of perception with which we are sur- 
rounded. So completely, however, is the mind 
in this particular subjected to physical laws, that 
it has been justly observed,* we cannot by an 
effort of our will call up any one thought, and 
that the train of our ideas depends on causes which 
operate in a manner inexplicable by us. 

This observation, although it has been censured 
as paradoxical, is almost self-evident; for, to call 
up a particular thought supposes it to be already 
1 Ibid., pp. 23-25. 2 By xx>rd Kames and others. 


in the mind. As I shall have frequent occasion, 
however, to refer to the observation afterwards, I 
shall endeavour to obviate the only objection which 
I think can reasonably be urged against it, and 
which is founded on that operation of the mind 
which is commonly called recollection or intentional 

It is evident, that before we attempt to recollect 
the particular circumstances of any event, that 
event in general must have been an object of our 
attention. We remember the outlines of the story, 
but cannot at first give a complete account of it. 
If we wish to recall these circumstances, there 
are only two ways in which we can proceed. We 
must either form different suppositions, and then 
consider which of these tallies best with the other 
circumstances of the event ; or, by revolving in 
our mind the circumstances we remember, we must 
endeavour to excite the recollection of the other 
circumstances associated with them. The first of 
these processes is, properly speaking, an inference 
of reason, and plainly furnishes no exception to 
the doctrine already delivered. We have an 
instance of the other mode of recollection, when we 
are at a loss for the beginning of a sentence in 
reciting a composition that we do not perfectly 
remember, in which case we naturally repeat over, 
two or three times, the concluding words of the 
preceding sentence, in order to call up the other 


words which used to be connected with them in 
the memory. In this instance, it is evident that 
the circumstances we desire to remember are not 
recalled to the mind in immediate consequence of 
an exertion of volition, but are suggested by some 
other circumstances with which they are connected, 
independently of our will, by the laws of our 

Notwithstanding, however, the immediate de- 
pendence of the train of our thoughts on the laws 
of association, it must not be imagined that the 
will possesses no influence over it. This influence, 
indeed, is not exercised directly and immediately, 
as we are apt to suppose on a superficial view of the 
subject ; but it is, nevertheless, very extensive in 
its effects, and the different degrees in which it is 
possessed by different individuals, constitute some 
of the most striking inequalities among men, in 
point of intellectual capacity. 

Of the powers which the mind possesses over the 
train of its thoughts, the most obvious is its power 
of singling out any one of them at pleasure, of 
detaining it, and of making it a particular object 
of attention. By doing so, we not only stop the 
succession that would otherwise take place, but in 
consequence of our bringing to view the less obvious 
relations among our ideas, we frequently divert the 
current of our thoughts into a new channel. If, for 
example, when I am indolent and inactive, the 

• STEWART 239 

name of Sir Isaac Newton accidentally occur to me, 
it will perhaps suggest one after another the names 
of some other eminent mathematicians and astrono- 
mers, or of some of his illustrious contemporaries 
and friends, and a number of them may pass in 
review before me, without engaging my curiosity 
in any considerable degree. In a different state of 
mind, the name of Newton will lead my thoughts 
to the principal incidents of his life, and the more 
striking features of his character ; or, if my mind 
be ardent and vigorous, will lead my attention to 
the sublime discoveries he made, and gradually 
engage me in some philosophical investigation. 
To every object, there are others which bear 
obvious and striking relations ; and others, also, 
whose relation to it does not readily occur to us, 
unless we dwell upon it for some time, and place it 
before us in different points of view. 

But the principal power we possess over the train 
of our ideas, is founded on the influence which our 
habits of thinking have on the laws of Association ; 
an influence which is so great, that we may often 
form a pretty shrewd judgment concerning a 
man's prevailing turn of thought, from the transi- 
tions he makes in conversation or in writing. It 
is well known, too, that by means of habit, a parti- 
cular associating principle may be strengthened 
to such a degree, as to give us a command of all 
the different ideas in our mind which have a certain 


relation to each other, so that when any one of the 
class occurs to us, we have almost a certainty that 
it will suggest the rest. What confidence in his 
own powers must a speaker possess, when he rises 
without premeditation in a popular assembly, to 
amuse his audience with a lively or a humorous 
speech ! Such a confidence, it is evident, can only 
arise from a long experience of the strength of 
particular associating principles. 

To how great a degree this part of our constitution 
may be influenced by habit, appears from facts which 
are familiar to every one. A man who has an am- 
bition to become a punster, seldom or never fails 
in the attainment of his object ; that is, he seldom 
or never fails in acquiring a power which other men 
have not, of summoning up on a particular occasion 
a number of words different from each other in 
meaning, and resembling each other more or less 
in sound. I am inclined to think that even genuine 
wit is a habit acquired in a similar way ; and 
that, although some individuals may from natural 
constitution be more fitted than others to acquire 
this habit, it is founded in every case on a peculiarly 
strong association among certain classes of our ideas, 
which gives the person who possesses it a command 
over those ideas which is denied to ordinary men. 
But there is no instance in which the effect of 
habits of association is more remarkable than in 
those men who possess a facility of rhyming. That 


a man should be able to express his thoughts 
perspicuously and elegantly, under the restraints 
which rhyme imposes, would appear to be incredible 
if we did not know it to be fact. Such a power 
implies a wonderful command both of ideas and of 
expression, and yet daily experience shews that 
it may be gained with very little practice. Pope 
tells us with respect to himself, that he could express 
himself not only more concisely but more easily in 
rhyme than in prose. 

Nor is it only in these trifling accomplishments 
that we may trace the influence of habits of associa- 
tion. In every instance of invention, either in the 
fine arts, in the mechanical arts, or in the sciences, 
there is some new idea, or some new combination 
of ideas, brought to light by the inventor. This, 
undoubtedly, may often happen in a way which he 
is unable to explain ; that is, his invention may be 
suggested to him by some lucky thought, the origin 
of which he is unable to trace. But when a man 
possesses a habitual fertility of invention in any 
particular art or science, and can rely, with con- 
fidence, on his inventive powers, whenever he is 
called upon to exert them, he must have acquired, 
by previous habits of study, a command over certain 
classes of his ideas, which enables him at pleasure 
to bring them under his review. ^ 

1 " Elements of the Philosophy of the Human Mind," Works, 
vol. ii. pp. 266-269- 




In order to illustrate a little farther the influence 
of the Association of Ideas on the human mind, I 
shall add a few remarks on some of its effects on 
our active and moral principles. In stating these 
remarks, I shall endeavour to avoid, as much as 
possible, every occasion of controversy, by con- 
fining myself to such general views of the subject, 
as do not presuppose any particular enumeration 
of our original principles of action, or any par- 
ticular system concerning the nature of the moral 
faculty. If my health and leisure enable me to 
carry my plans into execution, I propose, in the 
sequel of this work, to resume these inquiries, and 
to examine the various opinions to which they have 
given rise. 

The manner in which the association of ideas 
operates in producing new principles of action, 
has been explained very distinctly by different 
writers. Whatever conduces to the gratification 
of any natural appetite, or of any natural desire, is 
itself desired on account of the end to which it is 
subservient ; and by being thus habitually associ- 
ated in our apprehension with agreeable objects, it 
frequently comes, in process of time, to be regarded 
as valuable in itself, independently of its utility. 


It is thus that wealth becomes, with many, an 
ultimate object of pursuit ; although, at first, it is 
undoubtedly valued merely on account of its 
subserviency to the attainment of other objects. 
In like manner, men are led to desire dress, equipage, 
retinue, furniture, on account of the estimation 
in which they are supposed to be held by the 
public. Such desires are called by Dr Hutcheson ^ 
secondary desires, and their origin is explained by 
him in the way which I have mentioned. " Since 
we are capable," says he, " of reflection, memory, 
observation, and reasoning, about the distant 
tendencies of objects and actions, and not confined 
to things present, there must arise, in consequence 
of our original desires, secondary desires of every- 
thing imagined useful to gratify any of the primary 
desires ; and that with strength proportioned to 
the several original desires, and imagined usefulness 
or necessity of the advantageous object." " Thus," 
he continues, '* as soon as we come to apprehend 
the use of wealth or power to gratify any of our 
original desires, we must also desire them; and 
hence arises the universality of these desires of 
wealth and power, since they are the means of 
gratifying all other desires." The only thing that 
appears to me exceptionable in the foregoing 
passage is, that the author classes the desire of 
power with that of wealth ; wherccis I apprehend 

^ See his Essay on the Nature and Conduct of the Passions. 


it to be clear (for reasons which I shall state in 
another part of this work) that the former is a 
primary desire, and the latter a secondary one. 

Our moral judgments, too, may be modified, and 
even perverted to a certain degree, in consequence 
of the operation of the same principle. In the 
same manner in which a person who is regarded 
as a model of taste may introduce, by his example, 
an absurd or fantastical dress ; so a man of splendid 
virtues may attract some esteem also to his im- 
perfections ; and, if placed in a conspicuous 
situation, may render his vices and follies objects of 
general imitation among the multitude. 

" In the reign of Charles II.," says Mr Smith, ^ 
** a degree of licentiousness was deemed the char- 
acteristic of a liberal education. It was connected, 
according to the notions of those times, with 
generosity, sincerity, magnanimity, loyalty ; and 
proved that the person who acted in this manner 
was a gentleman, and not a puritan. Severity of 
manners and regularity of conduct, on the other 
hand, were altogether unfashionable, and were 
connected, in the imagination of that age, with 
cant, cunning, hypocrisy, and low manners. To 
superficial minds, the vices of the great seem at all 
times agreeable. They connect them not only with 
the splendour of fortune, but with many superior 
virtues which they ascribe to their superiors ; with 

1 Theory of Moral Sentiments. 


the spirit of freedom and independency ; with 
frankness, generosity, humanity, and poHteness. 
The virtues of the inferior ranks of people, on the 
contrary, — their parsimonious frugahty, their pain- 
ful industry, and rigid adherence to rules, seem to 
them mean and disagreeable. They connect them 
both with the meanness of the station to which 
these qualities commonly belong, and with many 
great vices which they suppose usually accompany 
them, such as an abject, cowardly, ill-natured, 
lying, pilfering disposition." 

The theory which, in the foregoing passages 
from Hutcheson and Smith, is employed so justly 
and philosophically to explain the origin of our 
secondary desires, and to account for some per- 
versions of our moral judgments, has been thought 
sufficient, by some later writers, to account for the 
origin of all our active principles without exception. 
The first of these attempts to extend so very far 
the application of the doctrine of Association, was 
made by the Rev. Mr Gay, in a Dissertation con- 
cerning the Fundamental Principle of Virtue, which 
is prefixed by Dr Law to his translation of Arch- 
bishop King's Essay on the Origin of Evil. In this 
dissertation, the author endeavours to shew, *' that 
our approbation of morality, and all affections 
whatsoever, are finally resolvable into reason, 
pointing out private happiness, and are conversant 
only about things apprehended to be means tending 


to this end ; and that wherever this end is not 
perceived, they are to be accounted for from the 
association of ideas, and may properly be called 
habits." The same principles have been since 
pushed to a much greater length by Dr Hartley, 
whose system (as he himself informs us) took rise 
from his accidentally hearing it mentioned as an 
opinion of Mr Gay, " that the association of ideas 
was sufficient to account for all our intellectual 
pleasures and pains." ^ 

It must, I think, in justice be acknowledged, 
that this theory concerning the origin of our 
affections, and of the moral sense, is a most in- 
genious refinement upon the selfish system, as it 
was formerly taught ; and that, by means of it, 
the force of 'many of the common reasonings 
against that system is eluded. Among these 
reasonings, particular stress has always been laid 
on the instantaneousness with which our affections 
operate, and the moral sense approves or condemns ; 
and on our total want of consciousness, in such 
cases, of any reference to our own happiness. The 
modern advocates for the selfish system admit the 
fact to be as it is stated by their opponents, and 

1 Mr Hume, too, who in my opinion has carried this principle 
of the Association of Ideas a great deal too far, had compared 
the universality of its applications in the philosophy of mind, to 
that of the principle of attraction in physics. " Here," says he, 
" is a kind of attraction, which in the mental world will be found 
to have as extraordinary effects as in the natural, and to shew 
itself in as many and as various forms." — Treatise of Human 
Nature, vol. i. p. 30. 


grant that, after the moral sense and our various 
affections are formed, their exercise, in particular 
cases, may become completely disinterested ; but 
still they contend, that it is upon a regard to our 
own happiness that all these principles are origin- 
ally grafted. The analogy of avarice will serve 
to illustrate the scope of this theory. It cannot be 
doubted that this principle of action is artificial. 
It is on account of the enjoyments which it 
enables us to purchase that money is originally 
desired ; and yet, in process of time, by means of 
the agreeable impressions which are associated 
with it, it comes to be desired for its own sake, 
and even continues to be an object of our pursuit, 
long after we have lost all relish for those enjoy- 
ments which it enables us to command. 

Without meaning to engage in any controversy 
on the subject, I shall content myself with observing 
in general, that there must be some limit beyond 
which the theory of association cannot possibly 
be carried ; for the explanation which it gives of the 
formation of new principles of action, proceeds on 
the supposition that there are other principles 
previously existing in the mind. The great ques- 
tion then is, when are we arrived at this limit ; or, 
in other words, when are we arrived at the simple 
and original laws of our constitution ? 

In conducting this inquiry philosophers have been 
apt to go into extremes. Lord Kames and some other 


authors have been censured, and perhaps justly, 
for a disposition to multiply original principles 
to an unnecessary degree. It may be questioned 
whether Dr Hartley and his followers have not 
sometimes been misled by too eager a desire of 
abridging their number. 

Of these two errors the former is the least common 
and the least dangerous. It is the least common, 
because it is not so flattering as the other to the 
vanity of a theorist ; and it is the least dangerous, 
because it has no tendency, like the other, to give 
rise to a suppression or to a misrepresentation of 
facts, or to retard the progress of the science by 
bestowing upon it an appearance of systematical 
perfection, to which in its present state it is not 

Abstracting, however, from these inconveniences 
which must always result from a precipitate re- 
ference of phenomena to general principles, it 
does not seem to me that the theory in question 
has any tendency to weaken the foundation of 
morals. It has, indeed, some tendency, in common 
with the philosophy of Hobbes and of Mandeville, 
to degrade the dignity of human nature, but it 
leads to no sceptical conclusions concerning the 
rule of life. For, although we were to grant that 
all our principles of action are acquired, so striking 
a difference among them must still be admitted, as 
is sufficient to distinguish clearly those universal 


laws which were intended to regulate human con- 
duct, from the local habits which are formed by 
education and fashion. It must still be admitted 
that while some active principles are confined to 
particular individuals, or to particular tribes of 
men, there are others which, arising from circum- 
stances in which all the situations of mankind must 
agree, are common to the whole species. Such 
active principles as fall under this last description, 
at whatever period of life they may appear, are to 
be regarded as a part of human nature no less than 
the instinct of suction ; in the same manner as 
the acquired perception of distance by the eye, is to 
be ranked among the perceptive powers of man, no 
less than the original perceptions of any of our 
other senses.^ 


I. It is by the immediate evidence of conscious- 
ness that we are assured of the present existence of 
our various sensations, whether pleasant or painful ; 
of all our affections, passions, hopes, fears, desires, 
and volitions. It is thus, too, we are assured of the 
present existence of those thoughts which, during 

^ " Elements of the Philosophy of the Human Mind," Works, 
vol. ii. pp. 334-338. 


our waking hours, are continually passing through 
the mind, and of all the different effects which they 
produce in furnishing employment to our intel- 
lectual faculties. 

According to the common doctrine of our best 
philosophers, it is by the evidence of consciousness 
we are assured that we ourselves exist. The 
proposition, however, when thus stated, is not 
accurately true ; for our own existence (as I have 
elsewhere observed) is not a direct or immediate 
object of consciousness, in the strict and logical 
meaning of that term. We are conscious of 
sensation, thought, desire, volition ; but we are not 
conscious of the existence of Mind itself ; nor 
would it be possible for us to arrive at the knowledge 
of it, (supposing us to be created in the full possession 
of all the intellectual capacities which belong to 
human nature), if no impression were ever to be 
made on our external senses. The moment that, 
in consequence of such an impression, a sensation 
is excited, we learn two facts at once, — the existence 
of the sensation, and our own existence as sentient 
beings ; — in other words, the very first exercise 
of consciousness necessarily implies a belief, not 
only of the present existence of what is felt, but of 
the present existence of that which feels and thinks : 
or (to employ plainer language) the present exist- 
ence of that being which I denote by the words / 
and myself. Of these facts, however, it is the former 


alone of which we can properly be said to be con- 
scious, agreeably to the rigorous interpretation of 
the expression. A conviction of the latter, al- 
though it seems to be so inseparable from the exer- 
cise of consciousness that it can scarcely be con- 
sidered as posterior to it in the order of time, is 
yet (if I may be allowed to make use of a scholastic 
distinction) posterior to it in the order of nature ; 
not only as it supposes consciousness to be already 
awakened by some sensation, or some other mental 
affection ; but as it is evidently rather a judgment 
accompanying the exercise of that power, than one 
of its immediate intimations concerning its appro- 
priate class of internal phenomena. It appears 
to me, therefore, more correct to call the belief of 
our own existence a concomitant or accessory of 
the exercise of consciousness, than to say, that our 
existence is a fact falling under the immediate 
cognizance of consciousness, like the existence of 
the various agreeable or painful sensations which 
external objects excite in our minds. 

2. That we cannot, without a very blameable 
latitude in the use of words, be said to be conscious 
of our personal identity, is a proposition still more 
indisputable ; inasmuch as the very idea of personal 
identity involves the idea of time, and consequently 
presupposes the exercise not only of consciousness, 
but of memory. The behef connected with this 
idea is impHed in every thought and every action 


of the mind, and may be justly regarded as one of 
the simplest and most essential elements of the 
understanding. Indeed, it is impossible to conceive 
either an intellectual or an active being to exist 
without it. It is, however, extremely worthy of 
remark, with respect to this belief that, universal 
as it is among our species, nobody but a meta- 
physician ever thinks of expressing it in words, or 
of reducing into the shape of a proposition the truth 
to which it relates. To the rest of mankind, it 
forms not an object of knowledge ; but a condition 
or supposition, necessarily and unconsciously in- 
volved in the exercise of all their faculties. On a 
part of our constitution, which is obviously one 
of the last or primordial elements at which it is 
possible to arrive in analyzing our intellectual 
operations, it is plainly unphilosophical to suppose 
that any new light can be thrown by metaphysical 
discussion. All that can be done with propriety, 
in such cases, is to state the fact. 

And here, I cannot help taking notice of the 
absurd and inconsistent attempts which some in- 
genious men have made, to explain the gradual 
process by which they suppose the mind to be led 
to the knowledge of its own existence, and of that 
continued identity which our constitution leads us 
to ascribe to it. How (it has been asked) does a 
child come to form the very abstract and meta- 
physical idea expressed by the pronoun / or moi ? 


In answer to this question, I have only to observe, 
that when we set about the explanation of a pheno- 
menon, we must proceed on the supposition that 
it is possible to resolve it into some more general 
law or laws with which we are already acquainted. 
But, in the case before us, how can this be expected, 
by those who consider that all our knowledge of 
mind is derived from the exercise of reflection ; and 
that every act of this power implies a conviction 
of our own existence as reflecting and intelligent 
beings ? Every theory, therefore, which pretends 
to account for this conviction, must necessarily 
involve that sort of paralogism which logicians call 
a petitio principii ; inasmuch as it must resolve the 
thing to be explained into some law or laws, the 
evidence of which rests ultimately on the assump- 
tion in question. From this assumption, . which is 
necessarily implied in the joint exercise of con- 
sciousness and memory, the philosophy of the 
human mind, if we mean to study it analytically, 
must of necessity set out ; and the very attempt 
to dig deeper for its foundation, betrays a total 
ignorance of the logical rules, according to which 
alone it can ever be prosecuted with any hopes of 

It was, I believe, first marked by M. Frevost of 
Geneva, (and the remark, obvious as it may appear, 
reflects much honour on his acuteness and sagacity) , 
that the inquiries concerning the mind, founded on 


the hypothesis of the animated statue — inquiries 
which both Bonnet and Condillac professed to 
carry on analytically — were in truth altogether 
synthetical. To this criticism it may be added, 
that their inquiries, in so far as they had for their 
object to explain the origin of our belief of our own 
existence, and of our personal identity, assumed, 
as the principles of their synthesis, facts at once 
less certain and less familiar than the problem 
which they were employed to resolve. 

Nor is it to the metaphysician only that the 
ideas of identity and of personality are familiar. 
Where is the individual who has not experienced 
their powerful influence over his imagination, while 
he was employed in reflecting on the train of events 
which have filled up the past history of his life ; and 
on that internal world, the phenomena of which 
have been exposed to his own inspection alone ? 
On such an occasion, even the wonders of external 
nature seem comparatively insignificant ; and one 
is tempted, (with a celebrated French writer), in 
contemplating the spectacle of the universe, to 
adopt the words of the Doge of Genoa, when he 
visited Versailles — " Ce qui m'^tonne le plus ici, 
c'est de m'y voir." ^ 

3. The belief which all men entertain of the 
existence of the material world, (I mean their belief 
of its existence independently of that of percipient 

1 D'Alembert, Apologie de I'^tude. 


beings,) and their expectation of the continued 
uniformity of the laws of nature, belong to the 
same class of ultimate or elemental laws of thought, 
with those which have been just mentioned. The 
truths which form their objects are of an order so 
radically different from what are commonly called 
truths, in the popular acceptation of that word, 
that it might perhaps be useful for logicians to 
distinguish them by some appropriate appellation, 
such, for example, as that of metaphysical or 
transcendental truths. They are not principles or 
data (as will afterwards appear) from which any 
consequence can be deduced ; but form a part of 
those original stamina of human reason, which are 
equally essential to all the pursuits of science, and 
to all the active concerns of life. 

4. I shall only take notice farther, under this 
head, of the confidence which we must necessarily 
repose in the evidence of memory, (and, I may add, 
in the continuance of our personal identity,) when 
we are employed in carrying on any process of 
deduction or argumentation, — in following out, for 
instance, the steps of a long mathematical demon- 
stration. In yielding our assent to the conclusion 
to which such a demonstration leads, we evidently 
trust to the fidelity with which our memory has 
connected the different links of the chain together. 
The reference which is often made, in the course of 
a demonstration, to propositions formerly proved, 


places the same remark in a light still stronger ; 
and shews plainly that, in this branch of knowledge, 
which is justly considered as the most certain of 
any, the authority of the same laws of belief which 
are recognised in the ordinary pursuits of life is 
tacitly acknowledged. Deny the evidence of 
memory as a ground of certain knowledge, and you 
destroy the foundations of mathematical science 
as completely as if you were to deny the truth of 
the axioms assumed by Euclid. 

The foregoing examples sufficiently illustrate the 
nature of that class of truths which I have called 
Fundamental Laws of Human Belief, or Primary 
Elements of Human Reason. A variety of others, 
not less important, might be added to the list ; * 
but these I shall not at present stop to enumerate, 
as my chief object, in introducing the subject here, 
was to explain the common relation in which they 
all stand to deductive evidence. In this point of 
view, two analogies, or rather coincidences, between 
the truths which we have been last considering, 
and the mathematical axioms which were treated 
of formerly, immediately present themselves to 
our notice. 

I. From neither of these classes of truths can 
any direct inference be drawn for the farther en- 
largement of our knowledge. This remark has 

1 Such, for example, as our belief of the existence of efficient 
causes ; our belief of the existence of other intelligent beings 
besides ourselves, etc., etc. 


been already shewn to hold universally with respect 
to the axioms of geometry, and it applies equally 
to what I have called Fundamental Laws of 
Human Belief. From such propositions as these 
— / exist ; I am the same person to-day that I was 
yesterday ; the material world has an existence 
independent of my mind ; the general laws of nature 
will continue, in future, to operate uniformly as in 
time past — no inference can be deduced, any more 
than from the intuitive truths prefixed to the 
Elements of Euclid. Abstracted from other data, 
they are perfectly barren in themselves ; nor can 
any possible combination of them help the mind 
forward one single step in its progress. It is for 
this reason that, instead of calling them, with some 
other writers, first principles, I have distinguished 
them by the title of fundamental laws of belief) 
the former word seeming to me to denote, accord- 
ing to common usage, some fact, or some sup- 
position, from which a series of consequences may 
be deduced. 

If the account now given of these laws of belief be 
just, the great argument which has been commonly 
urged in support of their authority, and which 
manifestly confounds them with what are properly 
called principles of reasoning, is not at all applicable 
to the subject ; or at least does not rest the point 
in dispute upon its right foundation. If there 
were no first principles, (it has been said,) or in other 



words, if a reason could be given for everything, no 
process of deduction could possibly be brought 
to a conclusion. The remark is indisputably true ; 
but it only proves (what no logician of the present 
times will venture to deny) that the mathematician 
could not demonstrate a single theorem, unless 
he were first allowed to lay down his definitions ; 
nor the natural philosopher explain or account for 
a single phenomenon, unless he were allowed to 
assume, as acknowledged facts, certain general laws 
of nature. What inference does this afford in 
favour of that particular class of truths to which 
the preceding observations relate, and against 
which the ingenuity of modern sceptics has been 
more particularly directed ? If I be not deceived, 
these truths are still more intimately connected 
with the operations of the reasoning faculty than 
has been generally imagined ; not as the principles 
(apxai) from which our reasonings set out, and 
on which they ultimately depend, but as the 
necessary conditions on which every step of the 
deduction tacitly proceeds ; or rather (if I may use 
the expression) as essential elements which enter 
into the composition of reason itself. 

2. In this last remark I have anticipated, in some 
measure, what I had to state with respect to the 
second coincidence alluded to, between mathe- 
matical axioms, and the other propositions which 
I have comprehended under the general title of 


fundamental laws of human belief As the truth of 
axioms is virtually presupposed or implied in the 
successive steps of every demonstration, so, in 
every step of our reasonings concerning the order of 
Nature, we proceed on the supposition, that the 
laws by which it is regulated will continue uniform 
as in time past ; and that the material universe 
has an existence independent of our perceptions. 
I need scarcely add, that in all our reasonings what- 
ever, whether they relate to necessary or to con- 
. tingent truths, our own personal identity, and the 
evidence of memory, are virtually taken for granted. 
'These different truths all agree in this, that they 
are essentially involved in the exercise of our 
rational powers ; although, in themselves, they 
furnish no principles or data by which the sphere 
of our knowledge can, by any ingenuity, be enlarged. 
They agree farther in being tacitly acknowledged 
by all men, learned or ignorant, without any formal 
enunciation in words, or even any conscious 
exercise of reflection. It is only at that period 
of our intellectual progress when scientific arrange- 
ments and metaphysical refinements begin to be 
introduced, that they become objects of attention 
to the mind, and assume the form of propositions. 
In consequence of these two analogies or coin- 
cidences, I should have been inclined to comprehend, 
under the general title of axioms, all the truths 
which have been hitherto under our review, if the 


common usage of our language had not, in a great 
measure, appropriated that appellation to the 
axioms of mathematics ; and if the view of the sub- 
ject which I have taken, did not render it necessary 
for me to direct the attention of my readers to the 
wide diversity between the branches of knowledge 
to which they are respectively subservient. 

I was anxious also to prevent these truths from 
being all identified, in point of logical importance, 
under the same name. The fact is, that the one 
class (in consequence of the relation in which they 
stand to the demonstrative conclusions of geometry) 
are comparatively of so little moment, that the 
formal enumeration of them was a matter of 
choice rather than of necessity ; whereas the other 
class have unfortunately been raised, by the 
sceptical controversies of modern times, to a con- 
spicuous rank in the philosophy of the human 
mind. I have thought it more advisable, therefore, 
to bestow on the latter an appropriate title of their 
own ; without, however, going so far as to reject 
altogether the phraseology of those who have 
annexed to the word axiom a more enlarged mean- 
ing than that which I have usually given to it. 
Little inconvenience, indeed, can arise from this 
latitude in the use of the term ; provided only it be 
always confined to those ultimate laws of belief, 
which, although they form the first elements of 
human reason, cannot with propriety be ranked 


among the principles from which any of our scien- 
tific conchisions are deduced. 

Corresponding to the extension which some late 
writers have given to axioms, is that of the province 
which they have assigned to intuition ; a term 
which has been applied, by Dr Beattie and others, 
not only to the power by which we perceive the 
truth of the axioms of geometry, but to that by 
which we recognise the authority of the fundamental 
laws of belief, when we hear them enunciated in 
language. My only objection to this use of the word 
is, that it is a departure from common practice ; 
according to which, if I be not mistaken, the proper 
objects of intuition are propositions ' analogous to 
the axioms prefixed to Euclid's Elements. In some 
other respects, this innovation might perhaps be 
regarded as an improvement on the very limited 
and imperfect vocabulary of which we are able 
to avail ourselves in our present discussions.^ 

^ According to Locke, we have the knowledge of our own 
existence by intuition ; of the existence of God by demonstration ; 
and of other things by sensation. — Book iv. chap. ix. § 2. 

This use of the word intuition seems to be somewhat arbitrary. 
The reaUty of our own existence is a truth which bears as little 
analogy to the axioms of mathematics, as any other primary 
truth whatever. If the province of inttiition, therefore, be ex- 
tended as far as it has been carried by Locke in the foregoing 
sentence, it will not be easy to give a good reason why it should 
not be enlarged a Httle farther. The words intuition and demon- 
stration, it must not be forgotten, have both of them an etymo- 
logical reference to the sense of seeing ; and when we wish to 
express, in the strongest terms, the most complete evidence 
which can be set before the mind, we compare it to the light of 
noon-day ; — in other words, we compare it to what Mr Locke here 
attempts to degrade, by calling it the evidence of sensation. 


To the class of truths which I have here called 
laws of belief, or elements of reason, the title of 
principles of common sense was long ago given by 
Father Bufher, whose language and doctrine 
concerning them bears a very striking resemblance 
to those of some of our later Scottish logicians. 
This, at least, strikes me as the meaning which 
these writers in general annex to the phrase, al- 
though all of them have frequently employed it 
with a far greater degree of latitude. When thus 
limited in its acceptation, it is obviously liable, in 
point of scientific accuracy, to two very strong 
objections, both of which have been already 
sufficiently illustrated. The^ first is, that it applies 
the appellation of principles to laws of belief from 
which no inference can be deduced ; the second, 
that it refers the origin of these laws to^Conlmon 
Sense. Nor is this phraseology more agreeable to 
popular use than to logical precision. If we were 
to suppose an individual, whose conduct betrayed 
a disbelief of his own existence, or of his own iden- 
tity, or of the reality of surrounding objects, it 
would by no means amount to an adequate de- 
scription of his condition to say, that he was destitute 
of common sense. We should at once pronounce 
him to be destitute of reason, and would no longer 
consider him as a fit subject of discipline or of 
punishment. The former expression, indeed, would 
only imply that he was apt to fall into absurdities 


and improprieties in the common concerns of life. 
To denominate, therefore, such laws of belief as 
we have now been considering, constituent elements 
of human reason, while it seems quite unexception- 
able in point of technical distinctness, cannot be 
justly censured as the slightest deviation from our 
habitual forms of speech. On the same grounds, it 
may be fairly questioned, whether the word reason 
would not, on some occasions, be the best substitute 
which our language affords for intuition, in that 
enlarged acceptation which has been given to it of 
late. If not quite so definite and precise as might 
be wished, it would be at least employed in one of 
those significations in which it is already familiar 
to every ear ; whereas the meaning of intuition, 
when used for the same purpose, is stretched very 
far beyond its ordinary limits. And in cases of 
this sort, where we have to choose between two 
terms, neither of which is altogether unexception- 
able, it will be found much safer to trust to the 
context for restricting in the reader's mind what is 
too general, than for enlarging what use has accus- 
tomed us to interpret in a sense too narrow. 

I must add, too, in opposition to the high author- 
ities of Dr Johnson and Dr Beattie, that for many 
years past, reason has been very seldom used by 
philosophical writers, or, indeed, by correct writers 
of any description, as synonymous with the power 
of reasoning. To appeal to the light of human 


reason from the reasonings of the schools, is surely 
an expression to which no good objection can be 
made, on the score either of vagueness or of novelty. 
Nor has the etymological affinity between these 
two words the slightest tendency to throw any 
obscurity on the foregoing expression. On the 
contrary, this affinity may be of use in some of 
our future arguments, by keeping constantly in 
view the close and inseparable connexion which 
will be afterwards shown to exist between the two 
different intellectual operations which are thus 
brought into immediate contrast. ^ 

1 " Elements of the Philosophy of the Human Mind " {Works, 
vol. iii. pp. 40-51). 


Affections, 161-169. 
Ambition, 210. 
Analysis, 35, 232. 
Anatomy of the mind, 13, 30. 
Appetites, 163-169, 183-185. 
Arbitrary connections, 99-100. 
Aristotle, 53. 

Association of Ideas, 233 sqq. 
Attention, 71, 112, 238. 
Axioms, 95, 96, 121, 152, 158, 
220, 256-261. 

Bacon, Francis, 76, 230, 232. 
Beattie, 2 n., 9, 11, 17-19, 23, 
261, 263. 

extracts from, 217-226. 
Belief, 39 sqq., 44 sqq., 166, 189, 
191, 218, 219. 

laws of, 249 sqq. 
Benevolence, 161 sqq., 211. 
Bentley, 149. 
Berkeley, 3-10, 15, 16. 20, 51, 

79, 88, 188, 225. 
Blair, 11. 
Bonnet, 254. 
Brown, Thomas, 20. 
Buf&er, 262. 

Campbell, George, 2 n., 20. 
Cause, 6^ sqq., 76, 100 sqq., 117. 
Character, 176, 222. 
Choice, 169-171, 213, 235. 
Collier, Arthur, 188. 
Colour, 85 sqq. 

Common sense, 6-10, 15, 29, 
36, 37, 41, 45, 48, 50, 55, 
61, 79, 148-153, 166, 
189, 220 sqq., 262. 

Common understanding, 96- 
98, 115- 

Conception, 128-132. 

Condillac, 254. 

Conduct, 156, 157, 164, 166, 
168, 171, 174, 182, 184. 

Conscience, 177, 180, 182 sqq. 

Consequences as test of right 
and wrong, 170. 

Contingency, 135. 

Contingent truths, 152-157. 

Cousin, Victor, 22. 

D'Alembert, 254 n. 
Descartes, 4, 8, 29, 35, 53, 140, 

Desire, 162, 167, 169, 242. 
Duty, 168, 173, 181, 184. 

Epicurus, 52. 

Error, 156. 

Ether, loi. 

Euclid, 158, 220, 256, 261. 

Extension, 80 sqq. 

Falsehood, 130 sqq., 190 sqq. 
Feeling, 189 sqq., 218. 
Ferguson, 18, 23. 

extracts from, 197-213. 
Figure, 87-89. 



First cause, see God. 
First principles, 48, iii sqq. 
of contingent truths, 152- 

of necessary truths, 157- 
Fraser, A. Campbell, 23. 

Galileo, 202. 
Gay, 245. 

God, 102, 103, 105, 107, 117, I 
155, 164, 183, 186, 212. I 

Habit, 235, 239-241, 246. 
Hamilton, Sir William, 9, 20, 

21, 23. 
Happiness, 175, 209, 229, 245, 

Hartley, 246, 248. 
Hobbes, 206, 248. 
Honour, 175 sqq. 
Hume, 1-13, 18, 49, 52. 53, 74- 

79, 154, 161, 167, 187, 

189, 225, 246, 
Hutcheson, 243, 245. 
Hypotheses, 117. 

" Ideal philosophy," 2-10, 15, 
29, 35, 41-44, 50-55, 62, 

Ideas, 4 sqq., 51, 86, 233 sqq. 

Imagination, 40, 42, 131. 

Individuality, 56 sqq., 77, 108, 

Induction, 232. 
Instinct, 94, 223, 229. 
Interest, 173-175. 
Intuition, 113, 226, 261 sqq. 

Johnson, Dr, 149, 263. 
Jou£Eroy, 22. 

Judgment, 14-17, 43 sqq., 132 
sqq., 220. 
moral, 186 sqq. 

Kames, Lord, 104, 105, 106, 

236, 247. 
Kant, 10-17. 
Kepler, 202. 
King, Archbishop, 245. 

Laurie, Prof. H., 23. 
Laurie, Prof. S. S., 22. 
Laws, moral, 173. 
Laws of nature, 100 sqq., 211, 

Leibnitz, 106. 
Locke, 2-10, 20, 35, 46, 53, 86, 

125, 143-147, 261. 

M'Cosh, 23. 
Magnitude, 87-89. 
Malebranche, 35. 
Malevolence, 162. 
Mandeville, 248. 
Mathematics, 152, 158, 205, 
and morals, 159. 
Matter, 98 sqq., 104. 
Memory, 40-42, 154, 237, 251, 

Mental chemistry, 33. 
Method, 13, 28 sqq., 76, 152- 

158, 182, 230 sqq. 
Mill, James, 19 n. 
Monboddo, Lord, 18 n., 20. 
Moral sense, 159, 160, 177, 180. 
Morals, 161-194. 

Natural Principles of Belief, 
14-17, 39 sqq., iii sqq. 

Natural Realism, 9, 21, 22. 

Nature, 97 sqq., 157, 197 sqq., 
217, 229. 
state of, 206. 

Necessary truths, 1 57-161. 

Newton, 13, 67, loi, 202, 203, 
209, 239. 



Obligation, moral, 173 sqq. 
Oswald, James, 9, 11. 

Paracelsus, 29. 

Passions, 167, 172, 185. 

Perception, 84-100, 1 18-122. 
distinguished from sensa- 
tion, 90-91, 122-125. 

Perfection, 199 sqq. 

Peripatetics, 71, 129. 

Personal identity, see Individu- 
ality and Self. 

Plato, 20, 55. 

Pope, 241. 

Power, 66 sqq., 100 sqq., 155, 
164, 229. 

Provost, 253. 

Priestley, 11. 

Pringle-Pattison, Prof. A. S., 

Probability, 219. 
Progress, 197-213. 
Propositions, 158, 190, 
Prudence, 157-160, 172-174, 

185, 221. 

Qualities, external, 62 sqq. 
primary and secondary, 15, 

84, 125-128. 
tactual, 68, 78, 83. 
visual, 85, 86. 

Rational principles, 165 sqq., 

Reason, 220-226, 245. 
as regulative, 166 sqq. 
elements of, 256 sqq. 
Reflection, 34, 112, 144, 170, 

183, 187, 208, 253. 
Reid, 1-17, 19, 23. 
extracts from, 27-194. 

Relations, 58 sqq., 145 sqq. 

moral, 178, 186. 
Representative Perception, 4. 
Right and wrong, 180-185. 
Royer-CoUard, 22. 

Scepticism, 1-4, 18, 20, 41, 46, 

92, 225. 
Self, 56 sqq., 77, 113, 154, 250- 


Self-love, 163. 

Sensation, 37 sqq., 122-125. 
distinguished from percep- 
tion, 90-91, 122-125. 
from sensed quality, 78, 

Sidgwick, 10. 

Signs, 74 sqq., 82, 87, 89, 93, 

Simple apprehension, 13, 40, 

42, 43- 
Smell, 37 sqq., 60 sqq. 
Smith, Adam, 2 n., 244, 245. 
Society, 164, 204, 206, 209. 
Stewart, 18-20, 23. 

extracts from, 229-264. 
Suggestion, 14, 59 sqq., 80, 87. 
Sympathy, 169, 221. 
Synthesis, 232. 
System, 35, 210. 

Taste, 159-161. 
Truth, 130 sqq., 156, 190 sqq., 
217 sqq. 

Virtue, 174-177. 

War, 206, 207. 

Will, 104, 109, 155, 165, 167, 
179, 211, 235. 




^rv^ TO D^l^^oX Si BOR.OWBD 


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Umversity of California